Tag Archives: benefit-cost analysis

When Reasonable Policy Discussions Become Unreasonable Personal Attacks

Recently I was reminded of the controversy that erupted late in 2014 about remarks made by the distinguished health economist, Jonathan Gruber, professor at MIT for two decades. Professor Gruber, one of the country’s leading experts on health policy, had played an important role in the construction of the Obama administration’s Patient Protection and Affordable Care Act, subsequently derided by its political opponents as “Obamacare.”

A brief but intense political controversy and media feeding-frenzy erupted when videos surfaced in which Professor Gruber – largely in a series of academic seminars and conferences – explained how the Act was crafted and marketed in ways that would make it easier to develop political support. For example, he noted that insurance companies were taxed instead of patients, fundamentally the same thing economically, but vastly more palatable politically. He went on to note that this was possible because of “the lack of economic understanding of the American voter.” His key point was that the program’s “lack of transparency is a huge political advantage.” Is that a controversial or even unique observation?

A Truism of Political Economy

Any economist who has worked on the development or analysis of public policy – in areas ranging from health care policy to environmental policy to financial regulation – recognizes the truth of the key insight Gruber was communicating to his audiences. It is inevitably in the interests of the advocates of a policy to make the policy’s benefits transparent and to make its costs vague, even unobservable; just as it is in the interests of the opponents of a policy to make that policy’s benefits obscure and its costs as clear as the light of day.

The specific construction of hundreds of public policies are explained by this truism. In the United States, Corporate Average Fuel Economy Standards (or “CAFE standards”) have been a bipartisan Congressional success, despite the fact that the costs they place on the American public per unit of fuel savings are vastly greater than the costs of a commensurate increase in gasoline taxes. Likewise, when conservative opponents of CO2 cap-and-trade wanted to stop the House-passed bill in its tracks, they resorted to demonizing it as “cap-and-tax.”

So, the central lesson Professor Gruber was offering is hardly controversial, and its enunciation ought not lead to the terrible attacks that he suffered. He doesn’t need me to defend him, but he was unfairly demonized, simply because people disagreed with him politically regarding the merits of the public policy he had helped develop and support.

Unfortunately, I was reminded of this recently when I found myself subject to attempted demonization, because someone did not agree with a policy I supported. What happened to me is trivial compared with what Professor Gruber has gone through, but it prompts me to write about it today.

Can We Agree to Disagree?

I have written before at this blog about the reasons why I support my university’s decision not to divest its endowment of its fossil-fuel company holdings. I won’t repeat those arguments here, but will note that I have gone out of my way not to draw conclusions or make recommendations about what other universities or other institutions ought to do in this regard, including when I agreed to write an essay on the subject for Yale Environment 360. My analysis and conclusions were not developed in spite of my decades of research, teaching, and outreach on global climate change policy; rather, they were developed because of my years of work in this area.

There are people, some of whom I greatly respect, who have different perspectives on this issue, and have come to very different conclusions than have I. We have essentially agreed to disagree. They haven’t cast aspersions on me, nor I on them. As my writings on this topic have illustrated, there are many facets to the issue, including economics, politics, ethics, and even religion. No one has cornered the market on wisdom.

And What About the Keystone XL Pipeline?

Likewise, on a quite different topic, on January 8, 2015, Coral Davenport wrote a story in the New York Times about the political debates in Washington regarding the proposed Keystone XL pipeline, and stated that “… most energy and policy experts say the battle over Keystone overshadows the importance of the project as an environmental threat or an engine of the economy. The pipeline will have little effect, they say, on climate change, production of the Canadian oil sands, gasoline prices and the overall job market in the United States.” She went on to quote me (accurately) as having said, “The political fight about Keystone is vastly greater than the economic, environmental or energy impact of the pipeline itself. It doesn’t make a big difference in energy prices, employment or climate change either way.” What I said was consistent with the evidence at the time (note, however, that as oil prices fall, the possibility increases that the Canadian oil sands would be uneconomic to develop without the pipeline). Once again, the analysis is not one-dimensional, and reasonable people can respectfully disagree.

When Policy Debates Become Personal Attacks

But these two topics – the Keystone XL pipeline and fossil-fuel divestment – have increasingly become engulfed in highly-charged campaigns and exceptionally heated political debates. As part of this, my integrity was recently attacked, because of my views.  A young and – I’m sure – well-intentioned climate activist and journalist, writing in the Huffington Post, implied that my assessment in the New York Times of the Washington political debates regarding Keystone XL and my support for Harvard’s divestment policy, are because “Stavins has done consulting work for Chevron, Exelon, Duke Energy and the Western States Petroleum Association.”

The author of the Huffington Post piece selected those three companies and one trade association from a list of 92 “Outside Activities” that I voluntarily provide as a means of public disclosure. The author chose not to note that the vast majority of my outside engagements are with universities, think tanks, environmental advocacy NGOs, foundations, the U.S. Environmental Protection Agency, other federal agencies and departments, international organizations, and environment ministries around the world (not to mention a set of Major League Baseball teams, but that’s another story altogether).

But what about the four he did choose to highlight? First, I am very proud of my work supported by Chevron and the closely-related Western States Petroleum Association, in which I have carried out a series of analyses studying how to strengthen and improve California’s climate policy under AB-32. That’s right – developing and assessing ways to make the AB-32 cap-and-trade system and the related suite of “complementary policies” more environmentally effective, more cost-effective, and more equitable (I’ve written about this work several times at this blog).

Likewise, my work supported by Duke Energy began a decade ago when I helped the former CEO bring home to his senior management the importance of climate change and the importance of well-designed public policies (in particular, carbon cap-and-trade) to address it. All of my subsequent work supported by Duke Energy likewise has focused on the design of better market-based instruments – cap-and-trade – to reduce CO2 emissions.

And, finally, what about Exelon? This was interesting and important work I carried out with my friend and colleague, MIT Professor Richard Schmalensee, Dean Emeritus of the Sloan School of Management (I wrote about this work at this blog and at the Huffington Post). In 2011, with support from Exelon, Professor Schmalensee and I analyzed EPA’s proposals for new rules to regulate the interstate transport of sulfur dioxide and nitrogen oxides emitted from electric power generation facilities. You can read in detail about our multi-faceted assessment, but the bottom-line is that we provided strong support for a stringent rule. Our brief summary at the University of Pennsylvania’s RegBlog concludes: “In sum, while imposing incremental costs to achieve reductions in SO2 and NOX emissions, the Transport Rule would produce significant benefits in terms of improved health outcomes, and better environmental amenities and services, which studies estimate significantly outweigh the costs.”

Sadness and Empathy

It is nothing less than absurd – and, frankly, quite sad – that someone would suggest that my views on divestment and my New York Times quote on the politics of Keystone XL were somehow due to my having received previous support for analytical work for an oil company, a trade association, and two electric utilities. This was an unfortunate move to question my credibility and damage my reputation in a misguided attempt to demonize me, rather than engage in reasonable discussion and debate. Unfortunately, most of those who have read the activist/journalist’s original commentary and have possibly repeated his claims to others will not see the essay you have just read.

This is surely nothing compared with what Professor Gruber has gone through, but it has certainly increased my empathy for him, as well as my admiration.


Personal Attacks: An Even Sadder Epilogue

It’s nearly two months since I wrote the essay above, but a series of recent events prompts me to add this sad epilogue.  My family and I have recently been subject to cyber-bullying, harassment, and threats, because of my public stance in support of Harvard’s decision not to divest from its endowment portfolio its holdings of fossil-fuel company stocks.

In particular, the most recent message sent to me said in part: “You may be assured that I will have a lot to say about your vocal public support of Harvard’s fossil fuel investments, … and that I have a particular interest in making sure that [your] financial connections to the fossil fuel industry are made fully public …” This threat to tarnish my reputation by publicizing a supposed conflict of interest is striking for a number of reasons:

  • In several essays at this blog and elsewhere, I have carefully explained my reasons for supporting Harvard’s decision not to divest;
  • In several essays at this blog and elsewhere, I have been completely up front about receiving support for (publically available) analytical work I’ve carried out for private-sector companies (and have long provided a list of all outside engagements at my website);
  • In the essay above, I documented the fundamentally pro-environment, policy-analytic work I had done for the specific companies mentioned; and
  • The claim that my position regarding Harvard divestment has somehow been influenced by my work with an oil company and an industry trade association defies logic.

The last item on this list – the fundamental illogic of such a claim – merits explanation. People on all sides of the divestment issue (including leaders of the student movement, and including the person who wrote the threat I quoted above) acknowledge that divestment will have no direct financial impacts on the respective companies. Rather, the merit of divestment that is most frequently cited by supporters is its symbolic value. Because divestment has no financial impacts on the fossil-fuel companies, those companies don’t care much about it. They would not care one way or the other what I might have to say on the topic. Hence, even if I did want to curry favor with those companies, that would not lead me (or anyone else) to take a particular position on the divestment issue.

The more important question to ask is whether my research, teaching, and outreach initiatives on climate change economics and policy have been biased by my having carried out consulting assignments for an oil company and trade association (two of a hundred outside engagements over the past several years)? That is, if there really was a conflict of interest, then in an effort to make those companies happy, I would presumably pull my punches regarding recommendations of what does matter to those companies – public policies that will reduce their profits by increasing their costs of doing business and/or by reducing demand for their products. But nothing could be further from the truth!

For a decade or more, my research, teaching, and outreach have focused on more enlightened, stronger, and better climate change policies. I have been outspoken in regard to the pressing need for well-designed carbon-price instruments at the national and sub-national levels, and for the need for better, more effective international climate policies, both under the United Nations Framework Convention on Climate Change and through other venues. This is reflected in my published research, my teaching, and my outreach efforts, including through this blog.

It is ironic, offensive, and sad that anyone would suggest that my support of Harvard’s divestment position is somehow tied to my outside engagements. That suggestion – and the recent threats I have received – defies logic and is contradicted by the record.

What are the Benefits and Costs of EPA’s Proposed CO2 Regulation?

­On June 2nd, the Obama Administration’s Environmental Protection Agency (EPA) released its long-awaited proposed regulation to reduce carbon dioxide (CO2) emissions from existing sources in the electricity-generating sector.  The regulatory (rule) proposal calls for cutting CO2 emissions from the power sector by 30 percent below 2005 levels by 2030.  This is potentially significant, because electricity generation is responsible for about 38 percent of U.S. CO2 emissions (about 32 percent of U.S. greenhouse gas (GHG) emissions).

On June 18th, EPA published the proposed rule in the Federal Register, initiating a 120-day public comment period.  In my previous essay at this blog, I wrote about the fundamentals and the politics of this proposed rule (EPA’s Proposed Greenhouse Gas Regulation: Why are Conservatives Attacking its Market-Based Options?).  Today I take a look at the economics.

Cost-Effective, Perhaps – but Efficient?

The proposed rule grants freedom to implementing states to achieve their specified emissions-reduction targets in virtually any way they choose, including the use of market-based instruments (the White House has referenced cap-and-trade in this context, although somewhat obliquely as “market-based programs,” and state-level carbon taxes might also be acceptable – if any states were to include them in their plans to implement the regualtion).  Also, the proposal allows for multistate proposals and for states and regions to establish linkages among their state and multi-state market-based instruments.  Some questions remain regarding the temporal flexibility (banking and borrowing) that the proposed rule will allow, but it’s reasonable to conclude at this point that although EPA may not be guaranteeing cost-effectiveness, it is allowing for it, indeed facilitating it.  As Dallas Burtraw of Resources for the Future has said, the proposed rule ought to be judged to be potentially cost-effective.

Cost-effectiveness (achieving a given target at the lowest possible aggregate cost) is one thing, but economists – and possibly some other policy wonks – may wonder if the proposal is likely to be efficient (maximizing the difference between benefits and costs).  This is a much higher mountain to climb, and a particularly challenging one for a regional, national, or sub-national climate-change policy, given the global commons nature of the problem.

The Challenge of this Global Commons Problem

GHGs mix globally in the atmosphere, and so damages are spread around the world and are unaffected by the location of emissions.  This means that any jurisdiction taking action – a region, a country, a state, or a city – will incur the direct costs of its actions, but the direct benefits (averted climate change) will be distributed globally.  Hence, the direct climate benefits a jurisdiction reaps from its actions will inevitably be less than the costs it incurs, despite the fact that global climate benefits may be greater – possibly much greater – than global costs.

(An Aside:  This presents the classic free-rider problem of this ultimate global commons problem:  It is in the interest of no country to take action, but each can reap the benefits of any countries that do take action.  This is why international, if not global, cooperation is essential.  See the extensive work of the Harvard Project on Climate Agreements.)

On June 2nd, EPA released its 376-page Regulatory Impact Analysis (RIA) of the proposed “Clean Power Plan” rule, the same day it released the 645-page proposed rule itselfAn RIA is essentially a benefit-cost analysis, required for significant new Federal rules by a series of Executive Orders going back to the presidency of Jimmy Carter, and reaffirmed by every President since, including most recently President Obama.

Given the fundamental economic arithmetic of a global commons problem, it would be surprising – to say the least – if EPA were to find that the expected benefits of the proposed rule would exceed its expected costs, but this is precisely what EPA has found.  Indeed, its central estimate is of positive net benefits (benefits minus costs) of $67 billion annually in the year 2030 (employing a mid-range 3% discount rate).  How can this be?

Two Answers to the Conundrum

First, EPA does not limit its estimate of climate benefits to those received by the United States (or its citizens), but uses an estimate of global climate benefits.

Second, in addition to quantifying the benefits of climate change impacts associated with CO2 emissions reductions, EPA quantifies and includes (the much larger) benefits of human-health impacts associated with reductions in other (correlated) air pollutants.

Of course, even if benefits exceed costs at the given level of stringency of the proposed rule, it does not mean that the rule is economically efficient, because it could be the case that benefits would exceed costs by an even greater amount with a more stringent or with a less stringent rule.  However, if benefits are not greater than costs (negative net benefits), then the rule cannot possibly be efficient, so I will stick with the all-too-common Washington practice and simply ask whether the analysis indicates a winner or a loser at the proposed rule’s given level of stringency.  In other words, the question becomes, “Is the proposed rule welfare-enhancing (even if it is not welfare-maximizing)?”

Now, let’s take a look at the numbers from these two key aspects of EPA’s economic analysis and the issues surrounding the calculations.

U.S. versus Global Damages

There are surely ethical arguments (and possibly legal arguments) for employing a global damage estimate, as opposed to a U.S. damage estimate, in a benefit-cost analysis of a U.S. climate policy, but until recently all Regulatory Impact Analyses over several decades had focused exclusively on U.S. impacts.

In a recent working paper, “Determining the Proper Scope of Climate Change Benefits,” Ted Gayer, Vice President and Director of Economic Studies at the Brookings Institution, and Kip Viscusi, University Distinguished Professor of Law, Economics, and Management at Vanderbilt University, review the history of RIAs, including their virtually exclusive focus on national impacts (defined by geography or U.S. citizenship) in benefit and cost estimates of regulations.

In the context of a conventional RIA, it does seem strange – at least at first blush – to use a global measure of benefits of a U.S. regulation.  If this practice were applied in a consistent manner – that is, uniformly in all RIAs – it would result in some quite bizarre findings.  For example, a Federal labor policy that increases U.S. employment while cutting employment in competitor economies might be judged to have zero benefits!

Another example, this one courtesy of Tim Taylor via Ted Gayer:  Under global accounting, if a domestic climate policy had the unintended consequence of causing emissions and economic leakage (through relocation of some manufacturing to other countries), that would not be considered a cost of the regulation (and with diminishing marginal utility of income, it might be counted as a benefit)!

On the other hand, a counter-argument to this line of thinking is that the usual narrow U.S.-only geographic scope of an RIA is simply not appropriate for a global commons problem.  Otherwise, we would simply restate in economic terms the free-rider consequences of a global commons challenge.  In other words, a domestic-only RIA of a climate policy could have the effect of “institutionalizing free riding,” to quote my Harvard Kennedy School colleague, Professor Joseph Aldy.  Of course, if global benefits are to be included in a regulatory assessment, it can be argued that global costs (such as leakage) should also be considered.

I leave it to legal scholars and lawyers to debate the law, and I defer to the philosophers among us to debate the ethics, but let’s at least ask what the consequences would be for EPA’s analysis if a U.S climate benefits number were used, rather than a global number.  For this purpose, we can start with EPA’s estimates (from Table ES-7 on page ES-19 and Table ES-10 on page ES-23 of its Regulatory Impact Analysis of the proposed rule) for 2030 benefits and costs, using a mid-range 3% real discount rate.  The estimated (global) climate benefits of the rule are $31 billion.

In order to think about what the domestic climate benefits might be, we can turn to the Obama administration’s original calculation of the Social Cost of Carbon in 2010, where the Interagency Working Group estimated a central global value for 2010 of $19 per ton of CO2, and noted (and explained in more detail in a subsequent scholarly paper by several members of the Working Group) that U.S. benefits from reducing GHG emissions would be, on average, about 7 to 10 percent of global benefits across the scenarios analyzed with the one model that permitted such geographic disaggregation.

(The Interagency Working Group also suggested that if climate damages are simply proportional to GDP, then the U.S. share would be about 23%.  However, given the IPCC’s prediction of highly unequal geographic distribution of climate change effects worldwide, combined with the exceptionally heterogeneous nature of climate sensitivity among the world’s economies, which vary from those with trivial reliance on agriculture to those dominated by their agricultural sectors, I find the argument behind this second approach unconvincing.)

Taking the midpoint of the Obama Working Group’s 7-10% range, U.S. damages (benefits) may be estimated to be 8.5% of global damages, which would reduce the $31 billion reported in the new RIA to about $2.6 billion, which is considerably less than the RIA’s estimated total annual compliance costs of $8.8 billion (assuming that the states facilitate cost-effective actions).  This validates the intuition, explained above, that for virtually any jurisdiction, the direct climate benefits it reaps from its actions will be less than the costs it incurs (again, despite the fact that global climate benefits may be much greater than global costs).

There are plenty of caveats on both sides of this simple analysis.  One of the most important is that if the proposed U.S. policy were to increase the probability of other countries taking climate policy actions (which I believe is probably the case), then the impacts on U.S. territory of such foreign policy actions would merit inclusion even in a traditional U.S.-only benefit-cost analysis.  More broadly, although it has been traditional to use a U.S.-only benefits measure in RIAs, the current guidelines for carrying out these analyses from the Office of Information and Regulatory Affairs of the U.S. Office of Management and Budget (Circular A-4) requires that geographic U.S. benefit and cost estimates be provided, but also allows for the optional inclusion of global estimates.

Pending resolution (or more likely, discussion and debate) from lawyers and philosophers regarding the legal and ethical issue of employing domestic benefits versus global benefits in a climate regulation RIA, it is essential to recognize that there is an even more important factor that explains how EPA came up with estimates of significant positive net benefits (benefits exceeding costs) for the proposed rule (and would have even if a domestic climate benefits number had been employed), namely, the inclusion of (domestic) health impacts of other air pollutants, the emissions of which are correlated with those of CO2.

Correlated Pollutants and Co-Benefits

The Obama Administration’s proposed regulation to reduce CO2 emissions from the electric power sector is intended to achieve its objectives through a combination of less electricity generated (compared with a business-as-usual trajectory), greater dispatch of electricity from less CO2-intensive sources (natural gas, nuclear, and renewable sources, instead of coal), and more investment in low CO2-intensive sources.  Hence, it is anticipated that less coal will be burned than in the absence of the regulation (and more use of natural gas, nuclear, and renewable sources of electricity).  This means not only less CO2 being emitted into the atmosphere, but also decreased emissions of correlated local air pollutants that have direct impacts on human health, including sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), and mercury (Hg).

It is well known that higher concentrations of these pollutants in the ambient air we breathe – particularly smaller particles of particulate matter (PM2.5) – have very significant human health impacts in terms of increased risk of both morbidity and mortality.  The numbers dwarf the climate impacts themselves.  Whereas the U.S. climate change impacts of CO2 reductions due to the proposed rule in 2030 are probably less than $3 billion per year (see above), the health impacts (co-benefits) of reduced concentrations of correlated (non-CO2) air pollutants are estimated by EPA to be some $45 billion/year (central estimate)!  (By the way, I assume that the co-benefits estimated by EPA are based upon a comparison with a business-as-usual baseline that includes the effects of all existing EPA and state regulations for these same local air pollutants.  If not, the RIA will need to be revised.)

The Bottom Line

The combined U.S.-only estimates of annual climate impacts of CO2 ($3 billion) and health impacts of correlated pollutants ($45 billion) greatly exceed the estimated regulatory compliance costs of $9 billion/year, for positive net benefits amounting to $39 billion/year in 2030.  This is the key argument related to the possible economic efficiency of the proposed rule from the perspective of U.S. welfare.  If EPA’s global estimate of climate benefits ($31 billion/year) is employed instead, then, of course, the rule looks even better, with total annual benefits of $76 billion, leading to EPA’s bottom-line estimate of positive net benefits of $67 billion per year.  See the summary table below.

The Obama Administration’s proposed regulation of existing power-sector sources of CO2 has the potential to be cost-effective, and if you accept these numbers, it can also be welfare-enhancing, if not welfare-maximizing.

That said, I assume that proponents of the Obama Administration’s proposed rule will take this assessment of EPA’s Regulatory Impact Analysis as evidence of the sensibility of the rule, and opponents of the Administration’s proposed actions will claim that my assessment of the RIA provides evidence of the foolishness of EPA’s proposal.  So it is in our pluralistic system (not to mention, in the context of the political polarization that has gripped Washington on this and so many other issues).


Benefits and Costs of EPA’s Proposed Clean Power Plan Rule in 2030

(Mid-Point Estimates, Billions of Dollars)

Climate Change Impacts

Health Impacts (Co-Benefits) of Correlated Pollutants plus …



Domestic Climate Impacts

Global Climate Impacts

  Climate Change

$ 3

$ 31



  Health Co-Benefits



Total Benefits

$ 3

$ 31



Total Compliance Costs

$ 9

$ 9

$ 9

$ 9

Net Benefits (Benefits – Costs)

– $ 6

$ 22

$ 39

$ 67


EPA’s Proposed Greenhouse Gas Regulation: Why are Conservatives Attacking its Market-Based Options?

This week, the Obama Administration’s Environmental Protection Agency (EPA) released its long-awaited proposed regulation to reduce carbon dioxide (CO2) emissions from existing sources in the electricity-generating sector.  The regulatory (rule) proposal calls for cutting CO2 emissions from the power sector by 30 percent below 2005 levels by 2030.

The Fundamentals in Brief

Through a carefully designed formula, EPA’s proposal lists specific targets for each state, under Section 111(d) of the Clean Air Act. States are given broad flexibility for how to meet their targets, including:  increasing the efficiency of fossil-fuel power plants; switching electricity dispatch from coal-fired generating plants to natural gas-fired generating plants; developing new low-emissions generation, such as new natural gas combined cycle plants, more renewable sources (wind and solar), nuclear, or coal with carbon capture and storage; and more efficient end-use of electricity.

States are also given flexibility to employ (in their implementation plans to be submitted to EPA) any of a wide variety of policy instruments, including but by no means limited to market-based trading systems.  Furthermore, states can work together to submit multi-state plans.

The proposed regulation will be finalized after receipt of comments one year from now (June 30, 2015).  Then states will have until July 2016 to submit their plans, and can request one-year extensions (or two-year extensions for multi-state plans). Compliance commences in 2020.

A Big-Picture Assessment of the Proposed Rule

Let’s start by acknowledging that the proposed policy will be less effective environmentally and less cost-effective economically than the economy-wide approach the Administration previously tried with the Waxman-Markey bill, which passed the U.S. House of Representatives in 2009, but failed to receive a vote in the U.S. Senate.  Electricity generation is responsible for about 38 percent of U.S. CO2 emissions, and about 32 percent of U.S. greenhouse gas (GHG) emissions.

Given ongoing political polarization in Washington and the inability of Congress to approve that more comprehensive and more cost-effective approach, this is probably the best the administration could do.  Together with the motor-vehicle fuel efficiency and appliance energy efficiency standards previously put in place, this is certainly a step in the right direction.

More broadly, the importance of these U.S. moves in the international context should not be underestimated.  Although the United States accounts for only about 17% of global CO2 emissions (second to China’s 26% in 2010), these steps by the U.S. government can help international efforts to bring the large emerging economies (China, India, Brazil, Korea, South Africa, and Mexico) on board for a future (Paris, 2015) agreement under the Durban Platform for Enhanced Action.

Domestically, EPA’s proposed state-by-state approach does not guarantee cost-effectiveness, because under the formula employed, marginal abatement costs will initially vary across states.  However, freedom is given to the states to employ market-based instruments, in particular, cap-and-trade systems (with carbon taxes presumably also an option).  And EPA has emphasized its willingness to consider multi-state implementation plans (think, for example, of the existing Regional Greenhouse Gas Initiative – RGGI – the cap-and-trade system operating in nine northeast states; and the likelihood of a future linked policy bringing together California’s AB-32 cap-and-trade system with policies in Oregon and Washington).

The ability of states to develop under EPA’s rule such linked systems of market-based instruments, as well as the freedom for states and regions to subsequently establish linkages means that although EPA may not be guaranteeing cost-effectiveness, it is certainly allowing for it, indeed it is facilitating it.

Response from Environmental Advocacy Groups and Industry

Much of the response this week has not been surprising.  The major environmental advocacy groups have been supportive of the proposed rule, despite the fact that they would prefer even greater ambition.  Many in industry have also offered praise for the approach, particularly because of the flexibility that EPA has given for the means of achieving emissions reductions.  In fact, some electricity-sector executives have been supportive, precisely for this reason, and appear to be encouraging the adoption of cap-and-trade systems.  At a minimum, leading electric utilities, including some that are fossil-heavy, such as FirstEnergy Corporation and American Electric Power, Inc., have taken a “wait-and-see” attitude, rather than attacking the proposal.

Also not surprising has been strong opposition from the coal industry, as well as some prominent industry trade associations, including the U.S. Chamber of Commerce.  Once the rule has become final (about a year from now), lawsuits will surely be filed by some of these private industry opponents and by a number of resistant states.

I will leave it to the lawyers to comment on the likely grounds of those anticipated lawsuits, as well as their probabilities of success.  But, clearly, for the plan to succeed it will need to survive those legal challenges, which will work their way through the courts over several years.

Also, a significant change in the senate majority and in the party holding power after the next presidential election could result in progress being slowed to a crawl, if not the abandonment of the approach proposed by the current administration.

None of that is particularly surprising, but what should be surprising is the fact that conservative attacks on EPA’s proposed rule have focused, indeed fixated, on one of the options that is given to the states for implementation, namely the use of market-based instruments, that is, cap-and-trade systems.  Given the demonization of cap-and-trade as “cap-and-tax” over the past few years by conservatives, why do I say that this fixation should be surprising?

The Irony of Conservatives Targeting Cap-and-Trade

Not so long ago, cap-and-trade mechanisms for environmental protection were popular in Congress. Now, such mechanisms are denigrated. What happened?  Professor Richard Schmalensee (MIT) and I recently told the sordid tale of how conservatives in Congress who once supported cap and trade had come to lambast climate change legislation as “cap-and-tax.” Ironically, in doing this, conservatives have chosen to demonize their own market-based creation.

In the late 1980s, there was growing concern that acid precipitation – the result of SO2 and, to a lesser extent, nitrogen oxides (NOx) reacting in the atmosphere to form sulphuric and nitric acids – was damaging forests and aquatic ecosystems, particularly in the northeast U.S. and southern Canada. In response, the U.S. Congress passed (and President George H.W. Bush signed into law) the Clean Air Act Amendments of 1990. Title IV of this law established the SO2 allowance-trading system.

By the close of the 20th century, the SO2 allowance-trading system had come to be seen as both innovative and successful.  However, the successful enactment and implementation of the SO2 cap-and-trade system in 1990 combined with the subsequent Congressional defeat of CO2 cap-and-trade legislation 20 years later has produced a striking irony. Market-based, cost-effective policy innovation in environmental regulation – in particular, cap-and-trade – was originally championed and implemented by Republican administrations from that of President Ronald Reagan to that of President George W. Bush.  But in recent years, Republicans have led the way in demonizing cap-and-trade, particularly as an approach to limiting carbon emissions.

For a long time, market-based approaches to environmental protection, such as cap-and-trade, bore a Republican label.  In the 1980s, President Ronald Reagan’s EPA put in place a trading program to phase out leaded gasoline. It produced a more rapid elimination of leaded gasoline from the marketplace than had been anticipated, and at a saving of some $250 million per year, compared with a conventional no-trade, command-and-control approach. Not only did President George H.W. Bush successfully propose the use of cap-and-trade to cut SO2 emissions, his administration advocated in international forums the use of emissions trading to cut global CO2 emissions (a proposal initially resisted but ultimately adopted by the European Union). In 2005, President George W. Bush’s EPA issued the Clean Air Interstate Rule, aimed at reducing SO2 emissions by a further 70% from their 2003 level. Cap-and-trade was again the policy instrument of choice.

From Bi-Partisan Support to Ideological Polarization

When the Clean Air Act Amendments were being considered in the Congress in 1989-1990, political support was not divided on partisan lines. Indeed, environmental and energy debates from the 1970s through much of the 1990s typically broke along geographic lines, rather than partisan lines, with key parameters being degree of urbanization and reliance on specific fuel types. Thus, the Clean Air Act Amendments of 1990 passed the Senate by a vote of 89-11 with 87% of Republican members and 91% of Democrats voting yea, and passed the House of Representatives by a vote of 401-21 with 87% of Republicans and 96% of Democrats voting in support.

But twenty years later, when climate change legislation was receiving serious consideration in Washington, environmental politics had changed dramatically, with Congressional support for environmental legislation coming mainly to reflect partisan divisions. In 2009, the House of Representatives passed the American Clean Energy and Security Act of 2009 (H.R. 2454) – the Waxman-Markey bill – that included an economy-wide cap-and-trade system to cut CO2 emissions. The Waxman-Markey bill passed the House by a narrow margin of 219-212, with support from 83% of Democrats, but only 4% of Republicans. In July 2010, the Senate abandoned its attempt to pass companion legislation. In the process of debating this legislation, conservatives (largely Republicans and some coal-state Democrats) attacked the cap-and-trade system as “cap-and-tax,” much as an earlier generation of liberals had denigrated cap-and-trade as “selling licenses to pollute.”

It may be that some conservatives in Congress opposed climate policies because of disagreement about the threat of climate change or the costs of the policies, but instead of debating those risks and costs, they chose to launch an ultimately successful campaign to demonize and thereby tarnish cap-and-trade as an instrument of public policy, rendering it “collateral damage” in the wider climate policy battle.

Today that “scorched-earth” approach may have come back to haunt conservatives.  Have they now boxed themselves into a corner, unable to support the power of the marketplace to reduce their own states’ compliance costs under the new EPA CO2 regulation?  I hope not, but only time will tell.

On the Origins of Research

In response to my last essay at this web site, “On Becoming an Environmental Economist,” several readers suggested that someday I should write about the origins of my various research initiatives over the past 25 years.  Today, I’m doing that sooner than anyone might have expected!

This is feasible because — also quite recently — I was asked by my colleague, Hannah Riley Bowles, the instructor in the Harvard Kennedy School’s Doctoral Research Seminar, to make a presentation to the first-year students in the Ph.D. program in public policy on how research programs develop.  To prepare for this, I reflected on my research projects over the past 25 years since receiving my PhD in economics at Harvard and joining the Kennedy School faculty, and as I began to write some notes for my presentation, a flow chart of research origins, subjects, and products started to emerge.  You can view my PowerPoint presentation (you need to use Slide Show mode to see the animation) here.

In this essay, I describe the elements of that flow chart of research sources, topics, and selected publications (and provide some screen shots of the PowerPoint deck).

As will probably be apparent, I found the process of preparing for Professor Bowles’s seminar valuable, because it forced me – for the first time in 25 years – to step back and reflect systematically on the origins of my research projects and the connections among them.  So, I recommend this process to other researchers, as I think you may find it rewarding.  And, for would-be researchers, that is, PhD students, I hope the results below will be informative.

An Ex Post Exploration of How Research Programs Develop

In carrying out this ex post exploration of how research programs may develop, I identified eleven types of sources of research ideas and projects.  In approximate chronological order (but not necessarily in order of importance), these are:

      • Dissertation
      • Involvement with the Policy World
      • Picking Up on Someone Else’s Work
      • Conferences
      • Funders
      • Student Interest
      • Responding to Others’ Work
      • Teaching
      • Consulting
      • Class Assignment
      • Invitation

I begin with how my dissertation research subsequently led to several avenues of further research and writing.

Dissertation — Analyzing Land Use

My 1988 Ph.D. thesis examined econometrically the factors that had led to the dramatic depletion of forested wetlands in the southern United States over the previous five decades.  Before commenting on how my dissertation stimulated my subsequent research, I should acknowledge that my dissertation topic itself grew of out of some consulting work I was doing at the time for the Environmental Defense Fund, in particular an analysis for James T. B. Tripp of how U.S. Army Corps of Engineers flood control projects were providing economic incentives for landowners to convert their forested wetlands to agricultural croplands.

My dissertation led directly to a pair of journal articles published in 1990 in the American Economic Review (with Adam Jaffe) and the Journal of Environmental Economics and Management.  But more striking – given the theme of this essay – is that several years later I realized that the general econometric approach and simulation model could be applied to a very different question, namely, analyzing the anticipated costs of biological carbon sequestration as a means of reducing net concentrations of carbon dioxide (CO2) in the atmosphere, linked with global climate change.  That recognition led to another article in the American Economic Review (1999), and then to a series of other, related projects on carbon sequestration (with Richard Newell 2000, and with Ruben Lubowski and Andrew Plantinga 2006, both in the Journal of Environmental Economics and Management), as well as a broader research initiative on factors affecting land-use decisions (with Plantinga and Lubowski in the Journal of Urban Economics in 2002 and Land Economics in 2008).  More recent work with Andrew Plantinga and Robin Cross (that does not appear in the schematic below) has involved an econometric analysis of the concept and reality of “terroir” associated with the production of premium wines (American Economic Review 2011, Journal of Wine Economics 2011).

A Less Direct Legacy of Dissertation:  Economics of Technological Change

A fundamental aspect of the econometric modeling involved in some of the land-use models above, including my dissertation research, was the estimation of the parameters of an empirical distribution of some heterogeneous attribute of land parcels, such as potential crop revenue (due to varying land quality, for example).  As costs of production fall, for example, that distribution would be swept, with various parcels going into production at various points in time.  Adam Jaffe and I hoped that this same sort of model could be applied to the process of technological diffusion, that is, the process of gradual adoption of some new technology over time.

As it turned out, however, the model was less useful than we first thought it would be for analyzing the factors affecting technology diffusion, and so we abandoned it for that purpose.  But this led us to explore other conceptual and empirical approaches to assessing the factors that lead to the diffusion of environmental technologies.  We developed a new framework for comparing empirically the effects of alternative environmental policy instruments on the diffusion of new technology, including Pigouvian taxes, technology adoption subsidies, and technology standards, with an empirical application to the diffusion of thermal insulation in new home construction, comparing the effects of energy prices, insulation cost, and building codes (Journal of Environmental Economics and Management 1995).  Related work with Nolan Miller and Lori (Snyder) Bennear followed in 2003 (American Economic Review).

Given our interest in the diffusion (adoption) of energy-efficiency technologies, it was natural to think about exploring the factors that affect the innovation (commercialization) of such technologies.  A very different model was developed — with Richard Newell taking the lead as part of his Harvard dissertation research — and an empirical application was made to analyzing the innovation of specific household energy-consuming durable goods (such as water heaters and air conditioners).  This work appeared in the Quarterly Journal of Economics in 1999.

More broadly, our interest in the innovation and diffusion energy efficiency technologies led us to explore in a series of articles the so-called “energy paradox” of apparently slow diffusion of technologies that appear to pay for themselves, as well as other issues related to energy-efficiency technological change (Energy Journal 1994, Resource and Energy Economics 1994, Energy Policy 1994, Elsevier Handbook of Economics 2003, Ecological Economics 2005, Energy Economics 2006, and many others).  And, recently, with a resurgence of interest in the energy paradox in the context of global climate change, Richard Newell and I have launched a new research initiative, with support from the Alfred P. Sloan Foundation.

Because I’ve sought to describe the origins of my research somewhat chronologically, I began with my dissertation research.  The fact that several strands of research — some directly related and some indirectly related to my dissertation — subsequently emerged will surely not surprise academic readers of this essay.  However, a considerably greater influence (indeed, the most important influence) on my research portfolio has come from my involvement — not with fellow scholars — but with practitioners in the world of public policy.  That may come as a surprise to some readers, and it is to this illustration of the two-way street between research and practice to which I now turn.

Involvement with the Policy World

A phone call I received in the late spring of 1988 — a week before my Harvard graduation — from Senator Timothy Wirth (D-Colorado), and a meeting shortly thereafter in Washington with Senator Wirth and his long-time friend and colleague, Senator John Heinz (R-Pennsylvania) led to an agreement that I would direct for them a study intended to inform the Presidential debates on environmental policy in that election year — Project 88:  Harnessing Market Forces to Protect the Environment (and a follow-up study in 1991, Project 88 — Round II, Incentives for Action: Designing Market-Based Environmental Strategies).

Many pages could be written — and, indeed, many have been written — about the influence that Project 88, sponsored by Senators Wirth and Heinz, subsequently had on policy developments at the federal level in Washington (including the path-breaking SO2 allowance trading program in the 1990 Clean Air Act amendments), within many states, and internationally in locations ranging from the European Union to China.  But my purpose in this essay is to examine the origins of my research portfolio, and so I will turn instead to reflect on the ways my experience with Project 88 (and related policy engagements with the White House, the Congress, and others) stimulated new paths of my scholarly research.

One path of research activity soon focused on normative analysis of alternative policy instruments, including work on:  transaction costs in cap-and-trade markets (Journal of Environmental Economics and Management 1995), the effects of correlated uncertainty on the choice between price and quantity instruments (Journal of Environmental Economics and Management 1996), vintage-differentiated regulations (Stanford Environmental Law Journal 2006), and policy instruments in second-best settings (with Lori Bennear, Environmental and Resource Economics 2007).  [The work on correlated uncertainty also illustrates an example of another source of research ideas, namely picking up on research by someone else, because this work was directly inspired by a footnote in Professor Martin Weitzman‘s classic work on “Prices vs. Quantities” (Review of Economic Studies 1974).]

Another area of work on normative analysis of policy instruments focused broadly on market-based instruments (with Robert Hahn, American Economic Review 1992; with Richard Newell, Journal of Regulatory Economics 2003; and the Elsevier Handbook of Environmental Economics 2003).  Other work focused more specifically on cap-and-trade systems (Journal of Economic Perspectives 1998; with Robert Hahn, Journal of Law and Economics 2011; and with Richard Schmalensee, Journal of Economic Perspectives 2013).

A conceptually distinct path of research that also found its origins in my work on Project 88 has involved examinations of the positive political economy of environmental policy (with Robert Hahn, Ecology Law Quarterly 1991; with Nathaniel Keohane and Richard Revesz, Harvard Environmental Law Review 1998; with Robert Hahn and Sheila Olmstead, Harvard Environmental Law Review 2003).

Even this extensive set of research projects and publications that derive from my work on Project 88 — depicted in the figure above — understates the influence that my work on Project 88 with Senators Wirth and Heinz has had on my scholarly research over the years.  This is because much of my work on global climate change policy, for example, has in fact focused on the potential use of market-based instruments in that realm, but for purposes of this essay, I associate that later work on climate policy with two other origins, namely, conferences and funders.

Conferences and Funders

Gradually over the 25 years since receipt of my PhD, my research has evolved from diverse work across environmental and natural resources economics, to more and more focus each year on various aspects of global climate change and related public policies.

“Climate skeptics” and other opponents of action to address climate change have sometimes accused the research community of focusing on climate change because “that is where the money is.”  Although there are sound reasons for focusing on climate change other than the availability of funds (such as the importance of the problem, and the methodological challenges it poses), there is some partial truth to the accusation.  Indeed, numerous national governments and major philanthropic foundations have made it their goal to stimulate research (and action) on climate change.

One part of my work in this realm has been research on national and sub-national climate policy instruments, often focused on the design of market-based instruments, including but not limited to cap-and-trade mechanisms (Brookings Institution 2007; Harvard Environmental Law Review 2008; Oxford Review of Economic Policy 2008; and my work on the Intergovernmental Panel on Climate Change, Second, 1995, and Third, 2001, and Fifth Assessment Reports.

An invitation from the Doris Duke Charitable Foundation to propose and eventually direct an international research and outreach project on international climate policy architecture led to much (but not all) of my work on international climate policy cooperation (with Joseph Aldy and Scott Barrett, Climate Policy 2003; with Scott Barrett, International Environmental Agreements 2003: with Sheila Olmstead, American Economic Review 2006; three books with Joseph Aldy published by Cambridge University Press 2007, 2009, 2010; an article with Judson Jaffe and Matthew Ranson, Ecology Law Quarterly 2010; and ongoing work on the IPCC Fifth Assessment Report 2010-2014; and much more).

Student Interest

Many professors who are reading this essay will not be the least bit surprised to learn that another origin of research ideas has been interest expressed by graduate students.  Three important examples stand out in my case.

One I have already written about above.  When Richard Newell (my very first PhD student) came to Harvard for graduate school in 1993, he brought with him an abiding interest in the relationship between science, technology, and policy.  At the time, Adam Jaffe and I were continuing our work on the diffusion of energy-efficiency technologies, and then the U.S. Department of Energy (DOE) solicited proposals for research that could improve the modeling of technological change in integrated assessment models of climate change (so this covers two other origins — involvement with the policy world, and potential funding).  All of this came together in a joint research initiative, funded by DOE, which supported Newell’s dissertation research on factors affecting the pace and direction of energy-efficiency technology innovation.  This led to a subsequent publication with Jaffe and Newell (Quarterly Journal of Economics 1999), as well as series of other collaborations with Newell, which are on-going to this day.

In 1999, Sheila (Cavanagh) Olmstead came to the Harvard PhD program in public policy with a strong background and keen interests in water resources and water policy.  I brought on board Michael Hanemann, then a professor at the University of California at Berkeley, as a collaborator, and together we applied (successfully) to the National Science Foundation for a grant that supported Sheila’s dissertation research on econometrically estimating demand for municipal water in the presence of block-rate pricing schedules.  Not only did that lead directly to some published work (with Olmstead and Hanemann, Journal of Environmental Economics and Management 2007), but led indirectly to other research on water pricing(with Olmstead, Water Resources Research 2009).

The work on carbon sequestration and land use described above with Ruben Lubowski and Andrew Plantinga (Journal of Environmental Economics and Management 2006; Journal of Urban Economics 2002; Land Economics 2008) also deserves mention in this part of the essay, because it all grew out of Ruben Lubowski‘s PhD dissertation research at Harvard.

Responding to Others’ Work

I mentioned above an example of picking up on someone else’s work (in a positive sense), namely a footnote in Marty Weitzman’s classic 1974 article on “Prices vs Quantities” in which he noted that he was assuming statistical independence between marginal benefits and marginal costs, which stimulated me to relax that assumption and pursue the analysis (which led to my article on the effects of correlated uncertainty in 1996 in the Journal of Environmental Economics and Management).

By contrast, sometimes researchers can be stimulated to do work in order to question others’ previous work (and related conventional wisdom).  This was the case with my collaborative work examining the topic of “corporate social responsibility,” an area of scholarship that some colleagues and I believed was populated by research and writing that generated more heat than light.  A conference we organized at Harvard led to a subsequent book that examined Environmental Protection and the Social Responsibility of Firms:  Perspectives from Law, Economics, and Business (with Harvard Law School professor, Bruce Hay, and Harvard Business School professor, Richard Vietor, 2005).  Later, I took the next step with a follow-up article with Vietor and his Harvard Business School colleague, Forest Reinhardt (Review of Environmental Economics and Policy 2008), and another with Reinhardt (Oxford Review of Economic Policy 2010).


Classroom teaching can itself provide inspiration for research.  In 2002, I was teaching a small “reading and research course” for PhD students interested in environmental economics, and lamented one day that the increasingly popular concept of “sustainability” seemed to lack a clear definition or interpretation that made sense in economic terms.  I offered a possible economic interpretation in class, and within a week, two students — Gernot Wagner and Alexander Wagner (unrelated) — had written out a mathematically formalized version of my interpretation.  We collaborated on writing a brief article that provided background as well as further exploration (Economic Letters 2003).


It may (or may not) come as a surprise that consulting (work I do outside of my Harvard responsibilities, sometimes for compensation, sometimes not) can also lead to interesting research ideas.  In my case, this has led to my thinking more carefully — with collaborators — about the analytical methods that surround net present value analysis (also called, benefit-cost analysis).

This has led to a series of papers on various dimensions of net present value analysis in the environmental realm, including such topics as:  the meaning, limits, and value of the Kaldor-Hicks criterion (with Kenneth Arrow and others, Science 1996); the role of discounting (with Lawrence Goulder, Nature 2002); new benefit-estimation methods (with Paul Portney, Journal of Risk and Uncertainty 1994; and with Lori Bennear and Alexander Wagner, Journal of Regulatory Economics 2005); and the use of Monte Carlo analysis to incorporate uncertainty in regulatory impact analysis (with Judson Jaffe, Regulation and Governance 2007).

Also, as I mentioned at the outset, my 1988 dissertation topic had grown out of some consulting work I was doing at the time for the Environmental Defense Fund.

Class Assignments

Many of my PhD students over the years have written term papers for courses that led to manuscript that were eventually published in academic journals.  But in my own case, because my PhD training in economics at Harvard did not include any courses in environmental economics (none existed at the time, as you may have noted in my previous essay, “On Becoming an Environmental Economist”), the only example I can provide of this origin of research is in a different area, namely economic history.  This is an area in which I took two wonderful courses from Professor Jeffrey Williamson (about which I wrote in my previous post).  An econometric analysis I carried out for one of those courses — “A Model of English Demographic Change: 1573-1873” was subsequently published (Explorations in Economic History 1988).

Invitations (and other origins)

There’s a clear positive correlation between the onset of grey hair and the frequency of invitations to write articles (or books) for publication.  These have included:  an article with Don Fullerton on how economists view the environment in Nature (1998); an article on common property resources in the American Economic Review (2011); my ongoing column, “An Economic Perspective” in The Environmental Forum (2006-present); my blog, “An Economic View of the Environment,” which was launched in 2009; two books of my collected works, 1988-1999 and 2000-2011 (Edward Elgar 2001, 2013); and three editions of a book of selected readings in environmental economics (W. W. Norton 2000, 2005, 2012).

Results of an Ex Post Exploration of Research Origins

Putting all of that together in a single flow chart results in the figure below, which is much clearer in a PDF version.  You can also view the entire PowerPoint presentation (you need to use Slide Show mode to see the animation) here.

As I said at the outset, I found the process of preparing this slide deck for Professor Bowles’s seminar valuable, because it enabled me to step back and reflect systematically on the origins of my research initiatives over the years and the relationships among them.  I recommend this process to other academics, because I believe it can be rewarding.  And, for academics in-the-making, that is, PhD students, I hope this essay may be informative.

On Becoming an Environmental Economist

My essay this month represents a departure from my standard blog posts about a contemporary environmental policy issue.  Rather, it is of a more personal nature, and stems from the fact that the second volume of my collected papers has just been published by Edward Elgar, Economics of Climate Change and Environmental Policy:  Selected Papers of Robert N. Stavins, 2000-2011 (2013), a successor to the first volume, published in 2000, Environmental Economics and Public Policy:  Selected Papers of Robert N. Stavins, 1988-1999.

When the publisher invited me to collect my papers in these edited volumes, it was suggested that I write a personal introduction in which I might reflect on the professional path that led to my research and writing.  I did this, and the introductory chapter of the second volume contains my latest reflections on that path.  This essay essentially consists of an abbreviated version.  My hope is that some readers will find it of interest, particularly students and others who aspire to work in this exciting and growing field.

A Professional Path

Over the past two decades, environmental and resource economics has evolved from what was once a relatively obscure application of welfare economics to a prominent field of economics in its own right.  The number of articles on the natural environment appearing in mainstream economics periodicals has continued to increase, as has the number of economics journals dedicated exclusively to environmental and resource topics.  Likewise, the influence of environmental economics on public policy has increased significantly, particularly as greater use has been made of market-based instruments for environmental protection.

In retrospect, my own professional path may now appear somewhat direct, if not altogether linear, but it hardly seemed so as I traveled along it.  The path I describe below took me back and forth across the United States and to several continents, and it took me from physics to philosophy, to agricultural extension, to international development studies, to agricultural economics, and eventually to environmental economics.  It culminated in my receipt in 1988 of a Ph.D. degree in economics at Harvard University, where I have since been a faculty member at the John F. Kennedy School of Government.  During this time, much has changed in the profession.

Early Days at Harvard

The early ascendency of the field of environmental economics, during the period from 1970 to 1990, was centered within departments of agricultural and resource economics, mainly at U.S. universities, and at Resources for the Future (RFF), the Washington research institution.  Within most economics departments, however, environmental studies remained a relatively minor area of applied welfare economics.  So, when I enrolled in the Ph.D. program in Harvard’s Department of Economics in 1983, and when I received my degree five years later, no field of study was offered in the field of environmental or resource economics.

Fortunately, Harvard permitted its graduate students to develop an optional, self-designed field as one of two “special fields” on which they were to be examined orally before proceeding to dissertation research.  Without an active environmental economist in the Department of Economics (Robert Dorfman had retired, and Martin Weitzman had yet to move to Harvard from the Massachusetts Institute of Technology), I developed an outline and reading list of the field through correspondence with leading scholars from other institutions, most prominently Kerry Smith, then at North Carolina State University.  My proposal to prepare for and be examined in the special field of environmental and resource economics (along with econometrics) was approved by the Department’s director of graduate study, Dale Jorgenson.  So began my entry into the scholarly literature.

A Nurturing Environment at Cornell

But my interest in environmental economics pre-dated by a considerable number of years my matriculation at Harvard.  Like many others before and since, I came to the field because of a personal interest in the natural environment (the origin of which I describe below).  This personal interest evolved into a professional one while I was studying for an M.S. degree in agricultural economics at Cornell University in the late 1970’s, where my thesis advisor and mentor was Kenneth Robinson.  I had originally gone to Cornell to study for a professional degree in international development, but found agricultural economics more appealing, largely because of the opportunity to examine social questions with quantitative methods within a disciplinary framework.

The faculty at Cornell and the care given to graduate students (including masters students like me) were both outstanding.  Ken Robinson, my first mentor within the economics profession, became my ongoing role model for intellectual integrity.  It was a very sad day in 2010 when Professor Robinson passed away.

A course in linear algebra, brilliantly taught by S. R. Searle, inspired me to pursue quantitative methods of analysis, and I was fortunate to then have the opportunity to study econometrics with Tim Mount.  One summer I had the great privilege of learning comparative economic systems in a small workshop setting from George Staller of the Cornell Department of Economics.   Working with Bud Stanton, I had my first experience teaching at the university level, and with Olan Forker, I had my first try at serious writing.  All of this led to research and writing of an M.S. thesis, “Forecasting the Size Distribution of Farms:  A Methodological Analysis of the Dairy Industry in New York State.”  The methodology in question was a variable Markov transition probability matrix, the cells of which were estimated econometrically in a multinomial logit framework.  Much to my surprise, this work subsequently received the Outstanding Master’s Thesis Award in the national competition of the American Agricultural Economics Association.

A Defining Move from Ithaca to Berkeley

Armed with my M.S. degree, I moved from Cornell to Berkeley, California, where I eventually met up with Phillip LeVeen, who had until shortly before that time been a faculty member in the Department of Agricultural and Resource Economics at the University of California, Berkeley.  Phil was another superb mentor, and from him I learned the power of using simple models — by which I mean a set of supply and demand curves hastily drawn on a piece of scrap paper — to develop insights into real-world policy problems.  He introduced me to a topic that was to occupy me for the next few years — California’s perpetual concerns with water allocation.  I remember many afternoons spent working with Phil at his dining room table on questions of water supply and demand.

This work with Phil LeVeen led to a consultancy and then a staff position with the Environmental Defense Fund (EDF), the national advocacy group consisting of lawyers, natural scientists, and — then almost unique among environmental advocacy organizations — economists.  At EDF, I was able to experience for the first time the use of economic analysis in pursuit of better environmental policy.  With W. R. Zach Willey, EDF’s senior economist in California, as a role model, and Thomas Graff, EDF’s senior attorney, as my mentor, I thrived in EDF’s collegial atmosphere, while thoroughly enjoying life in Berkeley’s “gourmet ghetto,” as my neighborhood was called.  Sadly, Tom Graff — without whose mentorship I would not be where I am today — passed away in 2009 after a heroic battle with cancer.

Although I found the work at EDF exceptionally rewarding, I worried that I would eventually be constrained — either within the organization or outside it — by my limited education.  So, like many others in similar situations, I considered a law degree as the next logical step.  In fact, I came very close to enrolling at Stanford Law School, but instead, in 1983, I accepted an offer of admission to the Department of Economics at Harvard, moved back east to Cambridge, Massachusetts, and began what has turned out to be a long-term relationship with the University.

Origins of Interest in Environmental Economics

But where did my interest in the natural environment begin?  Not at Cornell; it was present long before those days.  But it had not yet arisen when I was studying earlier at Northwestern University, from which I received a B.A. degree in philosophy, having departed from my first scholarly interest, astronomy and astrophysics.

Rather, the origins of my affinity for the natural environment and my interest in resource issues are to be found in the four years I spent in a small, remote village in Sierra Leone, West Africa, as a Peace Corps Volunteer, working in agricultural extension (in particular, paddy rice development).  It was there that I was first exposed both to the qualities of a pristine natural environment and the trade-offs associated with economic development.

So, I had begun in astrophysics, moved to philosophy (both at Northwestern), then to agricultural extension in a developing country (Sierra Leone), then to international development studies and subsequently to agricultural economics (both at Cornell), then to environmental economics and policy (EDF), and eventually to graduate study in economics at Harvard.

From Berkeley to Cambridge

My dissertation research at Harvard was directed by a committee of three faculty members:  Joseph Kalt, Zvi Griliches, and Adam Jaffe.  Joseph Kalt was the first faculty member at the Department of Economics to validate my interest in environmental and resource issues, and he was unfailingly generous to me and many other graduate students in making his office (and computer, then a rather scarce resource) available at all hours.  Now a colleague at the Kennedy School, Joe provided examples never to be forgotten — that economics could be a meaningful and enjoyable pursuit, and that excellence in teaching was a laudable goal.

Zvi Griliches was not only my advisor and mentor, but my spiritual father as well.  Generations of Harvard graduate students would offer similar testimony.  My own father had died only a year before I entered Harvard, and Zvi soon filled for me many paternal needs.  It is now more than a decade since Zvi himself passed away.  I felt as if I had lost my father a second time.

If Zvi Griliches provided caring and inspiration, Adam Jaffe provided invaluable day-to-day guidance.  It was Adam who convinced me not to go on the job market in my fourth year with what would have been a mediocre dissertation, but to put in another year and do it right.  That turned out to be some of the best professional advice I have ever received.  Our intensive faculty-student relationship from dissertation days subsequently evolved into a very productive professional (and personal) one that continues to this day.  The name of Adam Jaffe appears frequently in my curriculum vitae as a co-author; he has been and continues to be much more than that.

Although they were not members of my thesis committee, I should acknowledge two other faculty members at the Harvard Department of Economics who played important roles in my education.  I was fortunate to take two courses in economic history (a department requirement) from Jeffrey Williamson, who had recently arrived from the University of Wisconsin.  Williamson’s class sessions were as close as anything I have witnessed to being an economic research laboratory.  In class after class, we would carefully dissect one or more articles — examining hypothesis, theoretical model, data, estimation method, results, and conclusions.  If there was any place where I actually learned how to carry out economic research, it was in those classes.

The other name that is important to highlight is that of Lawrence Goulder, then a faculty member at Harvard, and now a professor at Stanford.  I say this not simply because he was willing to be my examiner in my chosen field of environmental and resource economics, nor because he subsequently became such a close friend.  Rather, what is striking about my professional relationship with Larry is the degree to which he has been an unnamed collaborator on so many projects of mine.  Although he and I have co-authored no more than a few articles, his name probably appears more frequently than anyone else’s in the acknowledgments of papers I have written.  There is no one whose overall judgement in matters of economics I trust more, and no one who has been more helpful.

First Steps for a Newly-Minted Ph.D. Recipient

When I began graduate school at Harvard in 1983, it was my intention to return to EDF as soon as I received my degree.  But by my third year in the program, I had decided to pursue an academic career, although one that was heavily flavored with involvement in the real world of public policy.  Within the context of this professional objective, it was not a difficult decision to accept the offer I received in February, 1988, to become an Assistant Professor at the Kennedy School.  Although some of the other offers I received at that time were also very attractive, the choice for me was obvious, and I have never regretted it — not for a moment.

I remain at the Kennedy School today, where I was promoted to Associate Professor in 1992 (an untenured rank at Harvard), and to a tenured position as Professor of Public Policy in 1997.   In 1998, I accepted an appointment as the Albert Pratt Professor of Business and Government.

Twenty-Five Years on the Harvard Faculty

Two years later, I launched the Harvard Environmental Economics Program, which today brings together — from across the University — thirty Faculty Fellows and twenty-five Pre-Doctoral Fellows, who are graduate students studying for the Ph.D. degree in economics, political economy and government, public policy, or health policy.  The Program, which I continue to direct, forms links among faculty and graduate students engaged in research, teaching, and outreach in environmental, natural resource, and energy economics and related public policy, by sponsoring research projects, convening workshops, and supporting graduate (and undergraduate) education.

A key reason why the Program — and its various projects, including the Harvard Project on Climate Agreements — have been so successful is the superb administrative leadership and staff support  it enjoys.  Everyone who has been involved in virtually any way has come away impressed by our Executive Director, Robert Stowe, and Program Manager, Jason Chapman.

At the Kennedy School, I have had an excellent mentor, William Hogan, and a superb advisor and friend, Richard Zeckhauser.  Over the years, five successive deans have provided leadership, guidance, and support (including abundant time for my research and writing) — Graham Allison, Robert Putnam, Albert Carnesale, Joseph Nye, and David Ellwood.  At Harvard more broadly, I have benefitted from regular interactions with Daniel Schrag, director of the Harvard University Center for the Environment, and Martin Weitzman of the Department of Economics.  For two decades, Marty and I have co-directed a bi-weekly Seminar in Environmental Economics and Policy, which has provided me with frequent opportunities to learn both from seminar speakers and from Marty’s questions and comments.  I will refrain from naming the many others at Harvard and elsewhere from whom I continue to learn — including my many co-authors — only because the list of such valued colleagues and friends is so long.  Included have been a most remarkable set of Ph.D. students, many of whom have gone on to productive — indeed illustrious — careers.

Along the way, I have had my share of administrative responsibilities at Harvard, including serving as Director of Graduate Studies for the Doctoral Program in Public Policy and the Doctoral Program in Political Economy and Government, and Co-Chair of the Harvard Business School-Harvard Kennedy School Joint Degree Programs.  Outside of Harvard, I have had the privilege of being a University Fellow of Resources for the Future, a Research Associate of the National Bureau of Economic Research, and the founding Editor and now Co-Editor of the Review of Environmental Economics and Policy, as well as a member of the Board of Directors of Resources for the Future, the Scientific Advisory Board of the Fondazione Eni Enrico Mattei, and numerous editorial boards. I must also note that I serve as an editor of the Journal of Wine Economics.  In 2009, I was elected a Fellow of the Association of Environmental and Resource Economists.

Working with the “Real World”

What originally attracted me to the Kennedy School was the possibility of combining an academic career with extensive involvement in the development of public policy.  I have not been disappointed.  Indeed, a theme that emerges from my collected papers is the interplay between scholarly economic research and implementation in real-world political contexts.  This is a two-way street.   In some cases, my policy involvement has come from expertise I developed through research, following a path well worn by academics.  But, in many other cases, my participation in policy matters has stimulated for me entirely new lines of inquiry.

What I have characterized as involvement in policy matters is described at the Kennedy School as faculty outreach, recognized to be of great institutional and social value, along with the two other components of our three-legged professional stool — research and teaching.  Because they relate to a number of the papers collected in this volume, I should note that my outreach efforts fall into five broad categories:  advisory work with members of Congress and the White House (for example, Project 88, a bipartisan effort co-chaired by former Senator Timothy Wirth and the late Senator John Heinz, to develop innovative approaches to environmental and resource problems); service on federal government panels (for example, my role as Chairman of the Environmental Economics Advisory Committee of the U.S. Environmental Protection Agency Science Advisory Board); on-going consulting — often on an informal basis — with environmental NGOs (most frequently, the Environmental Defense Fund) and private firms; advisory work with state governments; and professional interventions in the international sphere, such as service as a Lead Author for the Second and the Third Assessment Reports and a Coordinating Lead Author for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, professional roles with the World Bank and other international organizations, and advisory work with foreign governments.

Finally, because my two books of collected papers focus on my articles, not my books, I should note that over the years I have been privileged to be co-editor with Joseph Aldy of Post-Kyoto International Climate Policy:  Implementing Architectures for Agreement (Cambridge University Press, 2010), Post-Kyoto International Climate Policy:  Summary for Policymakers (Cambridge University Press, 2009), and Architectures for Agreement: Addressing Global Climate Change in the Post-Kyoto World (Cambridge University Press, 2007); editor of three editions of Economics of the Environment (W. W. Norton, 2000, 2005, 2012); co-editor with Bruce Hay and Richard Vietor of Environmental Protection and the Social Responsibility of Firms:  Perspectives from Law, Economics, and Business (Resources for the Future, 2005); editor of The Political Economy of Environmental Regulation (Edward Elgar, 2004), co-editor with Paul Portney of Public Policies for Environmental Protection (Resources for the Future, 2000); and author of Environmental Economics and Public Policy: Selected Papers of Robert N. Stavins, 1988-1999 (Edward Elgar, 2000).

The New Volume

That last book is the predecessor of the new volume.  Whereas the first volume (Stavins 2000) included selected papers from the period 1988 through 1999, the second volume covers the period from 2000 through 2011.  To prepare this new book, I selected 26 articles from the (many more) published papers I wrote  — frequently with co-authors — over the past decade.  Making this selection was not an easy task, but it was a rewarding one, because choosing the papers and organizing them has forced me to step back and reflect on the set of research endeavors in which I have been engaged over this decade, and thus to think more clearly about current and possible future directions.

The book is divided into seven parts.  The papers in Part I provide an overview of environmental and resource economics, treating broadly several key topics, including economic views of:  the problem of the commons (Stavins, American Economic Review, 2011); the history of U.S. environmental regulation (Hahn, Olmstead, and Stavins, Harvard Environmental Law Review, 2003); and corporate social responsibility (Reinhardt, Stavins, and Vietor, Review of Environmental Economics and Policy, 2008).

The articles in Part II deal with methods of environmental policy analysis, focusing, respectively, on:  interpreting sustainability in economic terms (Stavins, Wagner, and Wagner, Economic Letters, 2003); the use of discounting in net present value analysis (Goulder and Stavins, Nature, 2002); the development of a new revealed-preference method for inferring environmental benefits (Bennear, Stavins, and Wagner, Journal of Regulatory Economics, 2005); and the value of formal assessment of uncertainty (that is, Monte Carlo analysis) in regulatory impact analysis (Jaffe and Stavins, Regulation and Governance, 2007).

Part III turns to economic analysis of alternative environmental policy instruments, with examinations of: vintage-differentiated environmental regulation (Stavins, Stanford Environmental Law Journal, 2006); cost heterogeneity and the potential savings from employing market-based environmental policies (Newell and Stavins, Journal of Regulatory Economics, 2003); the effects of allowance allocations on the performance of cap-and-trade systems (Hahn and Stavins, Journal of Law and Economics, 2011); and second-best theory and the use of multiple policy instruments (Bennear and Stavins, Environmental and Resource Economics, 2007).

Part IV focuses on a topic that also received considerable treatment in the predecessor to this volume, namely the economics of technological change.  Here the articles include: a survey of the literature on environmental policy and technological change (Jaffe, Newell, and Stavins, Environmental and Resource Economics, 2002); an analysis of the interaction of environmental and technological market failures (Jaffe, Newell, and Stavins, Ecological Economics, 2005); an empirical assessment of the effect of environmental regulation on technology diffusion in the case of chlorine manufacturing (Miller, Snyder, and Stavins, American Economic Review Papers and Proceedings, 2003); and the effects of economic and policy incentives on carbon mitigation technologies (Jaffe, Newell, and Stavins, Energy Economics, 2006).

Part V consists of three articles in the area of natural resource economics dealing with land and water resources:  an analysis of the factors driving land-use change in the United States (Lubowski, Plantinga, and Stavins, Land Economics, 2008); an econometric examination of the significance of terroir, the notion that wine quality is primarily determined by location (Cross, Plantinga, and Stavins, American Economic Review Papers and Proceedings, 2011); and an assessment of urban water demand under alternative pricing structures (Olmstead, Hanemann, and Stavins, Journal of Environmental Economics and Management, 2007).

Part VI consists of four articles on domestic (national and sub-national) climate change policy, beginning with a description and assessment of a comprehensive U.S. cap-and-trade system for carbon dioxide and other greenhouse gas emissions (Stavins, Oxford Review of Economic Policy, 2008), and followed by:  an examination of the interactions of national and sub-national climate policies (Goulder and Stavins, American Economic Review Papers and Proceedings, 2011); an econometric study of the carbon-sequestration supply function (Lubowski, Plantinga, and Stavins, Journal of Environmental Economics and Management, 2006); and an assessment of the factors that affect the costs of biological carbon sequestration (Newell and Stavins, Journal of Environmental Economics and Management, 2000).

Finally, Part VII focuses on the international dimensions of climate change policy, and consists of four articles:  a comparison of alternative global climate change policy architectures (Aldy, Barrett, and Stavins, Climate Policy, 2003); an assessment of the Kyoto Protocol (Stavins, Milken Institute Review, 2005); an examination of a promising post-Kyoto international climate regime (Olmstead and Stavins, American Economic Review Papers and Proceedings, 2006); and a detailed examination of a key element of emerging international climate policy architecture, namely the linkage of regional, national, and sub-national tradable permit systems (Ranson, Jaffe, and Stavins, Ecology Law Quarterly, 2010).

Reflections on Common Themes

Selecting the essays for this second volume of my papers permitted me to take note of some common themes that emerge from this decade of research and writing.  First, there is the value — or at least, the potential value — of economic analysis of environmental policy.  The cause of virtually all environmental problems in a market economy is economic behavior (that is, imperfect markets affected by externalities), and so economics offers a powerful lens through which to view environmental problems, and therefore a potentially effective set of analytical tools for designing and evaluating environmental policies.

A second message, connected with the first, is the specific value of benefit-cost analysis for helping to promote efficient policies.  Economic efficiency ought to be one of the key criteria for evaluating proposed and existing environmental policies.  Despite its limitations, benefit-cost analysis can be useful for consistently assimilating the disparate information that is pertinent to sound decision making.  If properly done, it can be of considerable help to public officials when they seek to establish or assess environmental goals.

Third, the means governments use to achieve environmental objectives matter greatly, because different policy instruments have very different implications along a number of dimensions, including abatement costs in both the short and the long term.  Market-based instruments are particularly attractive in this regard.

Fourth, an economic perspective is also of considerable value when reflecting on the use of natural resources, whether land, water, fisheries, or forests.  Excessive rates of depletion of these resources are frequently due to the nature of the respective property-rights regimes, in particular, common property and open-access.  Economic instruments — such as ITQ systems in the case of fisheries — can and have been employed to bring harvesting rates down to socially efficient levels.

Fifth and finally, policies for addressing global climate change — linked with emissions of carbon dioxide and other greenhouse gases — can benefit greatly from the application of economic thinking.  On the one hand, the long time-horizon of climate change, the profound uncertainty in links between emissions and actual damages, and the possibility of catastrophic climate change present significant challenges to conventional economic analysis.  But, at the same time, the ubiquity of energy generation and use in modern economies means that only market-based policies — essentially carbon pricing regimes — are feasible instruments for achieving truly meaningful emissions reductions.  Hence, despite the challenges, an economic perspective on this grandest of environmental threats is essential.

Final Words

On a personal level, the professional path I have taken offers some confirmation that research can influence public policy, and it also illustrates that involvement in public policy can stimulate new research.  The quest — both professional and personal — that took me from Evanston, Illinois, to Sierra Leone, West Africa, to Ithaca, New York, to Berkeley, California, and finally to Cambridge, Massachusetts suggests some consistency of purpose and even function.  I continue to find myself doing similar things, but in different contexts.  It is fair to say that my professional life has taken me along a path that has brought me home.  The words of T. S. Eliot (1943) ring true:

                                        We shall not cease from exploration
                                        And the end of all our exploring
                                        Will be to arrive where we started
                                        And know the place for the first time.

Selecting the papers for this volume forces me to reflect on the past and think more clearly about the future.  The twenty-six articles that comprise this book and the twenty-two essays that comprised the predecessor volume are the product of twenty-three wonderful years on the faculty of the Harvard Kennedy School.  During this time, I have continued to learn about environmental economics and related public policy from colleagues, collaborators, students, friends, and inhabitants of the ”real world” of public policy, individuals from government, private industry, advocacy groups, and the press.  I hope that my learning will continue.

Economics of the Environment

The Sixth Edition of Economics of the Environment: Selected Readings has just been published by W. W. Norton & Company of New York and London.  Through five previous editions, Economics of the Environment has served as a valuable supplement to environmental economics texts and as a stand-alone book of original readings in the field of environmental economics.  Nearly seven years have passed since the previous edition of this volume was published, and it is now more than three decades since the first edition appeared, edited by Robert and Nancy Dorfman.  The Sixth Edition continues this tradition.

Motivation and Audience

Environmental economics continues to evolve from its origins as an obscure application of welfare economics to a prominent field in its own right, which combines elements from public finance, industrial organization, microeconomic theory, and many other areas of economics.  The number of articles on the environment appearing in mainstream economics periodicals continues to increase, and more and more economics journals are dedicated exclusively to environmental and resource topics.

There has also been a proliferation of environmental economics textbooks for college courses.  Many are excellent, but none can be expected to provide direct access to timely and original contributions by the field’s leading scholars.  As most teachers of economics recognize, it is valuable to supplement the structure and rigor of a text with original readings from the literature.

Scope and Style

With that in mind, this new edition of Economics of the Environment consists of thirty-four chapters that instructors will find to be of great value as a complement to their chosen text and their lectures.  The scope is comprehensive, and the list of authors is a veritable “who’s who” of environmental economics, including:  Joseph Aldy, Kenneth Arrow, Trudy Cameron, Ronald Coase, Maureen Cropper, Peter Diamond, George Eads, Jeffrey Frankel, Rick Freeman, Don Fullerton, Lawrence Goulder, John Graham, Robert Hahn, Michael Hanemann, Jerry Hausman, Steven Kelman, Nathaniel Keohane, Alan Krupnick, Lester Lave, John Livernois, Eric Maskin, Leonardo Maugeri, Gilbert Metcalf, Richard Newell, Roger Noll, William Nordhaus, Wallace Oates, Sheila Olmstead, Elinor Ostrom, Karen Palmer, Ian Parry, Carl Pasurka, Robert Pindyck, William Pizer, Michael Porter, Paul Portney, Forest Reinhardt, Richard Revesz, Milton Russell, Michael Sandel, Richard Schmalensee, Steven Shavell, Jason Shogren, Kerry Smith, Robert Solow, Nicholas Stern, Laura Taylor, Richard Vietor, and myself.

The articles are timely, with more than 90 percent published since 1990, and half since 2005.  There are two completely new sections of the book, “Economics of Natural Resources” and “Corporate Social Responsibility,” and all of the chapters in the section on global climate change are new to the sixth edition.

In order to make the readings in Economics of the Environment accessible to students at all levels, one criterion I use in the selection process is that articles should not only be original and well written — and meet the highest standards of economic scholarship — but also be non-technical in their presentations.  Hence, readers will find virtually no formal mathematics in any of the book’s 34 chapters throughout its 733 pages.

The Path Ahead

Environmental economics is a rapidly evolving field.  Not only do new theoretical models and improved empirical methods appear on a regular basis, but entirely new areas of investigation open up when the natural sciences indicate new concerns or the policy world turns to new issues.  Therefore, this book remains a work in progress.  I owe a great debt to the teachers and students of previous editions who have sent their comments and suggestions for revisions.  Looking to future editions, I invite all readers — whether teachers, students, or practitioners — to send me any thoughts or suggestions for improvement.

In the meantime, if you’re interested finding out more about the book, immediately below is a chapter-by-chapter summary of the book.  Alternatively, you can check out the W. W. Norton or Amazon web sites.


Appendix:  A Summary of Economics of the Environment, Sixth Edition

Part I of the volume provides an overview of the field and a review of its foundations.  Don Fullerton and I start things off with a brief essay about how economists think about the environment (Nature 1998).  This is followed by the classic treatment of social costs and bargaining by Ronald Coase (Journal of Law and Economics 1960), and a new article by Jason Shogren and Laura Taylor on the important, emerging field of behavioral environmental economics (Review of Environmental Economics and Policy 2008).

The Costs of Environmental Protection

Part II examines the costs of environmental protection, which might seem to be without controversy or current analytical interest.  This is not, however, the case.  This section begins with a survey article by Carl Pasurka that reviews the theory and empirical evidence on the relationship between environmental regulation and so-called “competitiveness” (Review of Environmental Economics and Policy 2008).

A somewhat revisionist view is provided by Michael Porter and Class van der Linde, who suggest that the conventional approach to thinking about the costs of environmental protection is fundamentally flawed (Journal of Economic Perspectives 1995).  Karen Palmer, Wallace Oates, and Paul Portney provide a careful response (Journal of Economic Perspectives 1995).

The Benefits of Environmental Protection

In Part III, the focus turns to the other side of the analytic ledger — the benefits of environmental protection.  This is an area that has been even more contentious — both in the policy world and among scholars.  Here the core question is whether and how environmental amenities can be valued in economic terms for analytical purposes.

The book features a provocative debate on the stated-preference method known as “contingent valuation.”  Paul Portney outlines the structure and importance of the debate, Michael Hanemann makes the affirmative case, and Peter Diamond and Jerry Hausman provide the critique (all three articles are from the Journal of Economic Perspectives 1994).

In the final article in Part III, the book turns to a concept that is both very important in assessments of the benefits of environmental regulations and is also very widely misunderstood — the value of a statistical life.  In an insightful essay, Trudy Cameron seeks to set the record straight (Review of Environmental Economics and Policy 2010).

There are two principal policy questions that need to be addressed in the environmental realm:  how much environmental protection is desirable; and how should that degree of environmental protection be achieved.  The first of these questions is addressed in Part IV and the second in Part V.

The Goals of Environmental Policy:  Economic Efficiency and Benefit-Cost Analysis

In an introductory essay, Kenneth Arrow, Maureen Cropper, George Eads, Robert Hahn, Lester Lave, Roger Noll, Paul Portney, Milton Russell, Richard Schmalensee, Kerry Smith, and I ask whether there is a role for benefit-cost analysis to play in environmental, health, and safety regulation (Science 1996).

Then, Lawrence Goulder and I focus on an ingredient of benefit-cost analysis that non-economists seem to find particularly confusing, or even troubling — intertemporal discounting (Nature 2002).  Next, Robert Pindyck examines a subject of fundamental importance — the role of uncertainty in environmental economics (Review of Environmental Economics and Policy 2007).  Steven Kelman provides an ethically-based critique of benefit-cost analysis, which is followed by a set of responses (Regulation 1981).

Part IV concludes with an up-to-date essay by John Graham on the critical role of the U.S. Office of Management and Budget in federal regulatory impact analysis (Review of Environmental Economics and Policy 2008).

The Means of Environmental Policy:  Cost Effectiveness and Market-Based Instruments

Part V examines the policy instruments — the means — that can be employed to achieve environmental targets or goals.  This is an area where economists have made their greatest inroads of influence in the policy world, with tremendous changes having taken place over the past twenty  years in the reception given by politicians and policy makers to so-called market-based or economic-incentive instruments for environmental protection.

Lawrence Goulder and Ian Parry start things off with a broad-ranging essay on instrument choice in environmental policy (Review of Environmental Economics and Policy 2008).  Following this, I examine lessons that can be learned from the innovative sulfur dioxide allowance trading program, set up by the Clean Air Act Amendments of 1990 (Journal of Economic Perspectives 1998).  Finally, Michael Sandel provides a critique of market-based instruments, with responses offered by Eric Maskin, Steven Shavell, and others (New York Times 1997).

Economics of Natural Resources

Part VI consists of three essays on a new topic for this book — the economics of natural resources.  First, John Livernois examines the empirical significance of a central tenet in natural resource economics, namely the Hotelling Rule — the proposition that under conditions of efficiency, the scarcity rent (price minus marginal extraction cost) of natural resources will rise over time at the rate of interest (Review of Environmental Economics and Policy 2009).

Essays by Leonardo Maugeri (Review of Environmental Economics and Policy 2009) and Sheila Olmstead (Review of Environmental Economics and Policy 2010), respectively, examine two particularly important resources:  petroleum and water.

The next four sections of the book treat some timely and important topics and problems.

Corporate Social Responsibility and the Environment

Part VII examines corporate social responsibility and the environment, discussion of which has too often been characterized by more heat than light.  Forest Reinhardt, Richard Vietor, and I provide an overview of this realm from the perspective of economics, examining the notion of firms voluntarily sacrificing profits in the social interest.  In a second essay, Paul Portney provides a valuable empirical perspective (both are from the Review of Environmental Economics and Policy 2008).

Global Climate Change

Part VIII is dedicated to investigations of economic dimensions of global climate change, which may in the long term prove to be the most significant environmental problem that has arisen, both in terms of its potential damages and in terms of the costs of addressing it.  First, a broad overview of the topic is provided in a survey article by Joseph Aldy, Alan Krupnick, Richard Newell, Ian Parry, and William Pizer (Journal of Economic Literature 2010).

Next, William Nordhaus critiques the well-known Stern Review on the Economics of Climate Change, and Nicholas Stern and Chris Taylor respond (both are from Science 2007).  In the final essay in this section, Gilbert Metcalf examines market-based policy instruments that can be used to address greenhouse gas emissions (Journal of Economic Perspectives 2009).

Sustainability, the Commons, and Globalization

Part IX begins with Robert Solow’s economic perspective on the concept of sustainability.  This is followed by Elinor Ostrom’s development of a general framework for analyzing sustainability (Science 2009), and my own historical view of economic analysis of problems associated with open-access resources (American Economic Review 2011).  Then, Jeffrey Frankel draws on diverse sources of empirical evidence to examine whether globalization is good or bad for the environment (Council on Foreign Relations 2004).

Economics and Environmental Policy Making

The final section of the book, Part X, departs from the normative concerns of much of the volume to examine some interesting and important questions of political economy.  It turns out that an economic perspective can provide useful insights into questions that might at first seem to be fundamentally political.

Nathaniel Keohane, Richard Revesz, and I utilize an economic framework to ask why our political system has produced the particular set of environmental policy instruments it has (Harvard Environmental Law Review 1998).  Myrick Freeman reflects on the benefits that U.S. environmental policies have brought about since the first Earth Day in 1970 (Journal of Economic Perspectives 2002).  Lastly, Robert Hahn addresses the question that many of the articles in this volume raise:  what impact has economics actually had on environmental policy (Journal of Environmental Economics and Management 2000)?

Good News from the Regulatory Front

As each day passes, the upcoming November 2012 general elections produce new stories about potential Republican candidates for President, as well as stories about President Obama’s anticipated re-election campaign.  At the same time, the 2012 elections are already affecting Congressional debates, where each side seems increasingly interested in taking symbolic actions and scoring political points that can play to its constituencies among the electorate, rather than working earnestly on the country’s business.

The new Tea Party Republicans in the House of Representatives decry the “fact” that the U.S. Environmental Protection Agency (EPA) continues to promulgate “job-killing regulations” for made-up non-problems.  And Democrats in the Congress – not to mention the Administration – are eager to talk about “win-win” policies that will produce “clean energy jobs” and protect Americans from the evils of imported oil and gas.

Neither side seems willing to admit that environmental regulations bring both good news – a cleaner environment – and bad news – costs of compliance that affect not only businesses but consumers as well.  Sometimes the cost-side of proposed regulations dominates.  Those regulatory moves are – from an economic perspective – fundamentally unwise, since they make society worse off.  In other cases, the benefits of a proposed regulation more than justify the costs that will be incurred.  Such regulations are – to use a word now favored by President Obama –  a wise investment.  They make society better off.  Failure to take action on such opportunities is imprudent, if not irresponsible.  Just such an opportunity now presents itself with EPA’s Clean Air Transport Rule.

In an op-ed that appeared on April 25, 2011, in The Huffington Post (click here for link to the original op-ed), Richard Schmalensee and I assess this opportunity.  Rather than summarize (or expand on) our op-ed, I simply re-produce it below as it was published by The Huffington Post, with some hyperlinks added for interested readers.

For anyone who is not familiar with my co-author, Richard Schmalensee, please note that he is the Howard W. Johnson Professor of Economics and Management at MIT, where he served as the Dean of the Sloan School of Management from 1998 to 2007.  Also, he served as a Member of the President’s Council of Economic Advisers in the George H. W. Bush administration from 1989 to 1991.  By the way, in previous blog posts, I’ve featured other op-eds that Dick and I have written in The Huffington Post (“Renewable Irony”) and The Boston Globe (“Beware of Scorched-Earth Strategies in Climate Debates”).


An Opportunity for Timely Action:  EPA’s Transport Rule Passes the Test

by Richard Schmalensee and Robert Stavins

The Huffington Post, April 25, 2011

At a time when EPA regulations are under harsh attack, one new environmental regulation – at least – stands out as an impressive winner for the country.  Studies of the soon-to-be-finalized Clean Air Transport Rule have consistently found that the benefits created by the rule would far outweigh its costs.  By reducing sulfur dioxide and nitrogen oxide emissions from power plants in 31 states in the East and Midwest, the Transport Rule will create substantial benefits through lower incidence of respiratory and heart disease, improved visibility, enhanced agricultural and forestry yields, improved ecosystem services, and other environmental amenities.  According to EPA, these benefits will be 25 to 130 times greater than the associated costs.  We document this in our new report, “A Guide to Economic and Policy Analysis of EPA’s Transport Rule,” which was commissioned by the Exelon Corporation.

Despite the benefits offered by the Transport Rule, some argue that it – and other EPA regulations – will stifle economic growth and threaten the reliability of our electric power system.  However, a careful look at the evidence reveals that the Transport Rule is unlikely to create such risks.  Analyses of the Transport Rule have found that it need not lead to significant plant retirements.   Robust regulatory and market mechanisms ensure that the nation can meet emission targets while reliably meeting customer demand.

While compliance with the Transport Rule would – in some cases – require installation of new pollution control equipment, the capital expenditures required would comprise a small fraction of aggregate capital spending by the power industry.  In fact, because of the Transport Rule’s unique legal circumstances, in which the Courts have mandated that EPA replace a stringent predecessor, utilities have already begun to make pollution control investments needed to comply with the Transport Rule.

The Rule’s timing can also contribute to lowering its cost and supporting other policy goals.  Installation of the pollution control technologies needed to comply with the Rule could increase short-term employment.  Although the longer term job impacts are less clear, these short-term employment effects would complement other policy initiatives aimed at supporting the nation’s economic recovery.

EPA analysis estimates modest impacts on regional electricity rates, but reductions in health care expenditures could partially or fully offset these effects.  Expanded supplies of low-cost natural gas can also help lower the Transport Rule’s cost by providing a less costly substitute for power generated from coal.

Most importantly, actions taken to reduce emissions would create substantial health benefits.  Tens of thousands of premature deaths would be eliminated annually, as would millions of non-fatal respiratory and cardiovascular illnesses.  A diverse set of studies find that these health improvements will create $20 to over $300 billion in benefits annually.  And, while the Transport Rule is designed to reduce the impact of upwind emissions on downwind states, upwind states would also receive substantial health benefits from the cleaner air brought about by the Rule.  These upwind states have much to gain, because states with the highest emissions from coal-fired power plants are also among those with the greatest premature mortality rates from these emissions.

Along with these health benefits, the largest shares of short-term improvements in employment and regional economies are likely to accrue to the regions that are most dependent on coal-fired power, as they invest in new pollution control equipment.  Thus, while designed to help regions downwind of coal-fired power plants, the Transport Rule also offers substantial benefits to upwind states.

As the U.S. economy emerges from its worst recession since the Great Depression of the 1930s and faces an increasingly competitive global marketplace, regulation such as the Transport Rule that creates positive net benefits and allows industry flexibility in creating public goods can complement strategies intended to foster economic growth.  Such regulations are best identified by careful analyses to ensure that benefits truly exceed costs and avoid unfair impacts on particular groups or sectors.  The Transport Rule has undergone a series of such thorough assessments, and the results consistently indicate that it would create benefits that far exceed its costs.  Failure to take timely action on this opportunity would seem to be imprudent, if not irresponsible.


*Richard Schmalensee is the Howard W. Johnson Professor of Economics and Management at the Massachusetts Institute of Technology, a research associate of the National Bureau of Economic Research, and a fellow of the Econometric Society and the American Academy of Arts and Sciences.  He served as a member of the Council of Economic Advisers with primary responsibility for environmental and energy policy from 1989 through 1991.  Robert N. Stavins is the Albert Pratt Professor of Business and Government at the Harvard Kennedy School, a university fellow of Resources for the Future, a research associate of the National Bureau of Economic Research, and a fellow of the Association of Environmental and Resource Economists.  He served as chairman of the EPA’s Environmental Economics Advisory Committee from 1997 through 2002.  Their report, “A Guide to Economic and Policy Analysis of EPA’s Transport Rule,” which was commissioned by the Exelon Corporation, can be downloaded at: http://www.analysisgroup.com/uploadedFiles/Publishing/Articles/2011_StavinsSchmalansee_TransportRuleReport.pdf

Reflecting on a Century of Progress and Problems

As the first decade of the twenty-first century comes to a close, the problem of the commons is more important to our lives – and more central to economics – than a century ago when the first issue of the American Economic Review appeared, with an examination by Professor Katharine Coman of Wellesley College of “Some Unsettled Problems of Irrigation” (1911).  Since that time, 100 years of remarkable economic progress have accompanied 100 years of increasingly challenging problems.

As the U.S. and other economies have grown, the carrying-capacity of the planet – in regard to natural resources and environmental quality – has become a greater concern, particularly for common-property and open-access resources.  In an article that appears in the 100th anniversary issue of the American Economic Review (AER) “The Problem of the Commons:  Still Unsettled After 100 Years” – I focus on some important, unsettled problems of the commons.

100 Years of Economic Progress and More Challenging Environmental Problems

Within the realm of natural resources, there are special challenges associated with renewable resources, which are frequently characterized by open-access.  An important example is the degradation of open-access fisheries.  Critical commons problems are also associated with environmental quality, including the ultimate commons problem of the twenty-first century – global climate change.

Small communities frequently provide modes of oversight and methods for policing their citizens, a topic about which Professor Elinor Ostrom of Indiana University has written extensively.  But as the scale of society has grown, commons problems have spread across communities and even  across nations.  In some of these cases, no over-arching authority can offer complete control, rendering commons problems more severe.

Although the type of water allocation problems of concern to Coman have frequently been addressed by common-property regimes of collective management, less easily governed problems of open-access are associated with growing concerns about air and water quality, hazardous waste, species extinction, maintenance of stratospheric ozone, and – most recently – the stability of the global climate in the face of the steady accumulation of greenhouse gases.

Whereas common property resources are held as private property by some group, open-access resources are non-excludable.  My article in the AER focuses exclusively on the latter, and thereby reflects on some important, unsettled problems of the commons.  It identifies both the contributions made by economic analysis and the challenges facing public policy.

The article begins with natural resources, highlighting the difference between most non-renewable natural resources, pure private goods that are both excludable and rival in consumption, and renewable natural resources, many of which are non-excludable.

Some of these are rival in consumption but characterized by open-access.  An example is the degradation of ocean fisheries. An economic perspective on these resources helps identify the problems they present for management, and provides guidance for sensible solutions.

The article then turns to a major set of commons problems that were not addressed until the last three decades of the twentieth century – environmental quality.  Although frequently characterized as textbook examples of externalities, these problems can also be viewed as a particular category of commons problems:  pure public goods, that are both non-excludable and non-rival in consumption.

A key contribution of economics has been the development of market-based approaches to environmental protection, including emission taxes and tradable rights.  These have potential to address the ultimate commons problem of the twenty-first century, global climate change.

Themes That Emerge

First, economic theory – by focusing on market failures linked with incomplete systems of property rights – has made major contributions to our understanding of commons problems and the development of prudent public policies.

Second, as our understanding of the commons has become more complex, the design of economic policy instruments has become more sophisticated, enabling policy makers to address problems that are characterized by uncertainty, spatial and temporal heterogeneity, and long duration.

Third, government policies that have not accounted for economic responses have been excessively costly, often ineffective, and sometimes counter-productive.

Fourth, commons problems have not diminished.  While some have been addressed successfully, others have emerged that are more important and more difficult.

Fifth, environmental economics is well positioned to offer better understanding and better policies to address these ongoing challenges.


Although I hope you will read the full article – which is very accessible — I will summarize its conclusions here.

Problems of the commons are both more widespread and more important today than when Coman wrote about unsettled problems in the first issue of the American Economic Review 100 years ago.  A century of economic growth and globalization have brought unparalleled improvements in societal well-being, but also unprecedented challenges to the carrying-capacity of the planet.  What would have been in 1911 inconceivable increases in income and population have come about and have greatly heightened pressures on the commons, particularly where there has been open access to it.

The stocks of a variety of renewable natural resources – including water, forests, fisheries, and numerous other species of plant and animal – have been depleted below socially efficient levels, principally because of poorly-defined property-right regimes.  Likewise, the same market failures of open-access – whether characterized as externalities, following A. C. Pigou (1920), or public goods, following Ronald Coase (1960) – have led to the degradation of air and water quality, inappropriate disposal of hazardous waste, depletion of stratospheric ozone, and the atmospheric accumulation of greenhouse gases linked with global climate change.

Over this same century, economics – as a discipline – has gradually come to focus more and more attention on these commons problems, first with regard to natural resources, and more recently with regard to environmental quality.  Economic research within academia and think tanks has improved our understanding of the causes and consequences of excessive resource depletion and inefficient environmental degradation, and thereby has helped identify sensible policy solutions.

Conventional regulatory policies, which have not accounted for economic responses, have been excessively costly, ineffective, or even counter-productive.  The problems behind what Garrett Hardin (1968) characterized as the “tragedy of the commons” might better be described as the “failure of commons regulation.”  As our understanding of the commons has become more complex, the design of economic policy instruments has become more sophisticated.

Problems of the commons have not diminished, and the lag between understanding and action can be long.  While some commons problems have been addressed successfully, others continue to emerge.  Some – such as the threat of global climate change – are both more important and more difficult than problems of the past.

Fortunately, economics is well positioned to offer better understanding and better policies to address these ongoing challenges.  As the first decade of the twenty-first century comes to a close, natural resource and environmental economics has emerged as a productive field of our discipline and one that shows even greater promise for the future.

Unintended Consequences of Government Policies: The Depletion of America’s Wetlands

Private land-use decisions can be affected dramatically by public investments in highways, waterways, flood control, or other infrastructure.  The large movement of jobs from central cities to suburbs in the postwar United States and the ongoing destruction of Amazon rain forests have occurred with major public investment in supporting infrastructure.  As these examples suggest, private land-use decisions can generate major environmental and social externalities – or, in common language, unintended consequences.

In an analysis that appeared in 1990 in the American Economic Review, Adam Jaffe of Brandeis University and I demonstrated that the depletion of forested wetlands in the Mississippi Valley – an important environmental problem and a North American precursor to the loss of South American rain forests – was exacerbated by Federal water-project investments, despite explicit Federal policy to protect wetlands.

Wetland Losses

Forested wetlands are among the world’s most productive ecosystems, providing improved water quality, erosion control, floodwater storage, timber, wildlife habitat, and recreational opportunities.  Their depletion globally is a serious problem; and preservation and protection of wetlands have been major Federal environmental policy goals for forty years.

From the 1950s through the mid-1970s, over one-half million acres of U.S. wetlands were lost each year.  This rate slowed greatly in subsequent years, averaging approximately 60 thousand acres lost per year in the lower 48 states from 1986 through 1997.  And by 2006, the Bush administration’s Secretary of the Interior, Gale Norton, was able to announce a net gain in wetland acreage in the United Sates, due to restoration and creation activities surpassing wetland losses.

What Caused the Observed Losses?

What were the causes of the huge annual losses of wetlands in the earlier years?  That question and our analysis are as germane today as in 1990, because of lessons that have emerged about the unintended consequences of public investments.

The largest remaining wetland habitat in the continental United States is the bottomland hardwood forest of the Lower Mississippi Alluvial Plain.  Originally covering 26 million acres in seven states, this resource was reduced to about 12 million acres by 1937.  By 1990, another 7 million acres had been cleared, primarily for conversion to cropland.

The owner of a wetland parcel faces an economic decision involving revenues from the parcel in its natural state (primarily from timber), costs of conversion (the cost of clearing the land minus the resulting forestry windfall), and expected revenues from agriculture.  Agricultural revenues depend on prices, yields, and, significantly, the drainage and flooding frequency of the land.  Needless to say, landowners typically do not consider the positive environmental externalities generated by wetlands; thus conversion may occur more often than is socially optimal.

Such externalities are the motivation for Federal policy aimed at protecting wetlands, as embodied in the Clean Water Act.  Nevertheless, the Federal government engaged in major public investment activities, in the form of U.S. Army Corps of Engineers and U.S. Soil Conservation Service flood-control and drainage projects, which appeared to make agriculture more attractive and thereby encourage wetland depletion.  The significance of this effect had long been disputed by the agencies which construct and maintain these projects; they attributed the extensive conversion exclusively to rising agricultural prices.

In an econometric (statistical) analysis of data from Arkansas, Mississippi, and Louisiana, from 1935 to 1984, Jaffe and I sought to sort out the effects of Federal projects and other economic forces.  We discovered that these public investments were a very substantial factor causing conversion of wetlands to agriculture, with between 30 and 50 percent of the total wetland depletion over those five decades due to the Federal projects.

More broadly, four conclusions emerged from our analysis.  First, landowners had responded to economic incentives in their land-use decisions.  Second, construction of Federal flood-control and drainage projects caused a higher rate of conversion of forested wetlands to croplands than would have occurred in the absence of projects, leading to the depletion of an additional 1.25 million acres of wetlands.  Third, Federal projects had this impact because they made agriculture feasible on land where it had previously been infeasible, and because, on average, they improved the quality of feasible land.  Fourth, adjustment of land use to economic conditions was gradual.

Government Working at Cross-Purposes

The analysis highlighted a striking inconsistency in the Federal government’s approach to wetlands.  In articulated policies, laws, and regulations, the government recognized the positive externalities associated with some wetlands, with the George H.W. Bush administration first enunciating a “no net loss of wetlands” policy.  But public investments in wetlands – in the form of flood-control and drainage projects – had created major incentives to convert these areas to alternative uses.  The government had been working at cross-purposes.

The conclusion that major public infrastructure investments affect private land-use decisions (thereby often generating negative externalities) may not be a surprise to some readers, but it was the 1990 analysis described here that first provided rigorous evidence which contrasted sharply with the accepted wisdom among policy makers.

The Ongoing Importance of Induced Land-Use Changes

As wetlands, tropical rain forests, barrier islands, and other sensitive environmental areas become more scarce, their marginal social value rises.  In general, if induced land-use changes are not considered, the country will engage in more public investment programs whose net social benefits are negative.

Can Countries Cut Carbon Emissions Without Hurting Economic Growth?

In the September 21st issue of the Wall Street Journal, the editors pose the following question: can countries cut carbon emissions without hurting economic growth? In his introductory essay, Michael Totty frames the issues as follows:

“There’s little doubt: Cutting greenhouse gases will be costly. But that leads to two big questions. First, how costly? And second, can nations afford it? As policy makers around the world take action to avoid a predicted climate catastrophe, the debate is turning to the costs of reducing carbon-dioxide emissions. Energy-efficiency measures are often pricey, and alternative energy sources are more expensive than the fossil fuels they replace. A steep price on carbon emissions will ripple through the economy. Does that mean a serious effort to tackle global warming is incompatible with economic growth? Or can we make significant cuts in greenhouse-gas emissions without causing serious damage to the economy?

We put the question to a pair of experts. Robert Stavins, a professor of business and government at Harvard University and director of Harvard’s environmental economics program, says the answer to the second question is yes: Making the necessary cuts need cause little more than a blip in world-wide growth if smart policies are used.

Steven Hayward, a fellow at the American Enterprise Institute for Public Policy Research, says no: Energy use — and the carbon dioxide it emits — is so central to the world’s economy that major cuts can’t be made without significant damage.

Of course, the answers can depend in large part on how “significant cuts” and “serious damage” are defined. Many scientists, the European Parliament and the Waxman-Markey climate legislation approved by the U.S. House of Representatives have set a goal of cutting carbon emissions about 80% by 2050, so that was picked as constituting significant cuts.

As the accompanying essays show, such a definition leaves plenty of room for disagreement.”

I encourage you to read the entire Journal Report on Environment in the Wall Street Journal (there’s an excellent Q&A on carbon offsets by Bob Curran) and to check out my affirmative response, “Yes: The Transition Can be Gradual — and Affordable,” as well as Steven Hayward’s well-articulated negative response, “No: Alternatives are Simply Too Expensive.”

Understandably, the editors wanted to highlight differences between us in order to develop a concise and clear debate. I find it interesting, however, that in an audio interview/debate at the Wall Street Journal web site (Podcast: Crafting a Global Policy), which was by nature more free-wheeling and less limited by space constraints, there is a remarkable amount of agreement between Mr. Hayward and me on a number of key issues.

For now, in today’s post — liberated from space constraints — I want to expand a bit on my WSJ essay, in which I responded, yes, the transition can be gradual and affordable.

Can the nations of the world meaningfully address the threat of global climate change without inflicting unjustifiable damage to their economies? The answer that has emerged with increasing clarity is a resounding “yes.”

Although “The Day After Tomorrow,” the 2004 disaster epic about the greenhouse effect’s apocalyptic consequences, had less scientific basis than “The Wizard of Oz,” scientific reality is disturbing enough. Man-made emissions of greenhouse gases — including carbon dioxide (CO2) from the combustion of fossil fuels — are very likely to change the earth’s climate in ways that most people will regret. World energy trends are unsustainable — environmentally, economically, and socially.

The global recession has slowed emissions growth, but the world is on a path to more than double global atmospheric greenhouse gas (GHG) concentrations to 1,000 parts per million (ppm) in CO2-equivalent terms by the end of the century, resulting in an average global temperature increase of 6 degrees Centigrade. But increased temperatures — which might well be welcome in some places — are only part of the story.

The most important consequences of climate change will be changes in precipitation (causing, for example, 75 to 250 million people in Africa to be exposed to increased water stress due to climate change by 2020, with rain-fed agriculture yields falling by as much as 50%), disappearance of glaciers throughout the world (and decreased snowpack in areas ranging from the western United States to Asia), droughts in mid to low latitudes (with severe effects in Australia), decreased productivity of cereal crops (at lower latitudes, especially in tropical regions), increased sea level, loss of islands and 30% of global coastal wetlands, increased flooding (in all parts of the world, but greatest in Asia), greater storm frequency and intensity (both typhoons and hurricanes), risk of massive species extinction (20 to 30% of all species, including massive coral mortality), and significant spread of infectious disease. On the other hand, climate change will also bring some health benefits to temperate areas, such as fewer deaths from cold exposure. But such benefits will be greatly outweighed by negative health effects of rising temperatures (cardo-respiratory, diarrhoeal, and infectious diseases, and increased morbidity and mortality from heat waves, floods, and droughts), especially in developing countries.

These impacts will have severe economic, social, and political consequences for countries worldwide, ranging from malnutrition and mass migration (hundreds of millions of people displaced) to national security threats. Bottom-line, comprehensive estimates of economic impacts of unrestrained climate change vary, with most falling in the range of 2 to 5% of world GDP per year by the middle of the century. The best estimates of marginal damages of emissions (again, by mid-century) are in the range of $100 to $175 per ton of CO2 (in today’s dollars).

The world is already experiencing the adverse effects of increasing concentrations of GHGs in the atmosphere, with concentrations already about 60% above pre-industrial levels, greatly exceeding the natural range over the past 600,000 years. Just one example: the Greenland ice sheet has been losing mass at a rate of 179 billion tons per year since 2003.

To have a coin toss’s 50-50 chance of keeping temperature increases below 2 degrees Centigrade — the level at which the worst consequences of climate change can be avoided — it will be necessary to stabilize atmospheric concentrations at 450 ppm. (Even this would result in significant sea-level rise, species loss, and increased frequency of extreme weather, according to the U.N. Intergovernmental Panel on Climate Change.) Consistent with the 450 ppm goal is a long-range target of cutting U.S. emissions 80% below 2005 levels by 2050, which happens to be the target of legislation passed earlier this year by the U.S. House of Representatives, H.R. 2454, the so-called Waxman-Markey bill.

Now, to the heart of the WSJ question: will a serious effort to tackle global warming is incompatible with economic growth? My response was and is that the nations of the world do not have to wreck their economies to avert the crisis. If appropriate and intelligent policies are employed, the job can be done at reasonable and acceptable cost.

Critics argue that the Waxman-Markey legislation — to cut U.S. emissions 80% below 2005 levels by 2050 — will mean big, disruptive changes to our infrastructure and untold economic damage. But they make a couple of basic errors. For one thing, they seem to think we’d have to replace the entire infrastructure quickly, paying trillions of dollars to shift to cleaner power. They also seem to assume that we have to choose between much more expensive energy and no energy at all.

The move to greener power doesn’t have to be completed immediately, and it doesn’t have to be painful. The right transition plan will increase consumers’ bills gradually and modestly, and allow companies to make gradual, well-timed moves.

How would this work? One way is via a combination of national and multinational cap-and-trade systems. Companies around the world would be issued rights by their governments to produce carbon, which they could buy and sell on an open market. If they wanted to produce more carbon, they could buy another company’s rights. If they produced less carbon than they needed, they could sell their extra rights. What’s more, companies could earn more rights by creating appropriate “offsets” that mitigated their carbon use, such as planting forests. Nations could add carbon taxes to the mix.

The effect would be to send price signals through the market — making use of less carbon-intensive fuels more cost-competitive, providing incentives for energy efficiency and stimulating climate-friendly technological change, such as methods of capturing and storing carbon, as well as safe nuclear power.


Julian Puckett

Robert Stavins

More Efficient

True, in the short term changing the energy mix will come at some cost, but this will hardly stop economic growth. As economies have grown and matured, they have become more adept at squeezing more economic activity out of each unit of energy they generate and consume. Consider this: From 1990 to 2007, while world emissions rose 38%, world economic growth soared 75% — emissions per unit of economic activity fell by more than 20%.

Critics argue we can’t possibly increase efficiency enough to hit the 80% goal. In a very limited sense, that’s true. Efficiency improvements alone, like the ones that propelled us forward in the past, won’t get us where we need to go by 2050. But this plan doesn’t rely solely on boosting efficiency. It brings together a host of other changes, such as moving toward greener power sources. What’s more, making gradual changes means we don’t have to scrap still-productive power plants, but rather begin to move new investment in the right direction.

As for how much this will cost, the best economic analyses — including studies from the U.S. Congressional Budget Office and the U.S. Energy Information Administration — say such a policy in the U.S. could cost considerably less than 1% of gross domestic product per year in the long term, or up to $175 per household in 2020. (As the Obama administration is fond of saying, that’s about the cost of one postage stamp per household per day.)

In the end, we would be delaying 2050’s expected economic output by no more than a few months. And bear in mind that previous environmental actions, such as attacking smog-forming air pollution and cutting acid rain, have consistently turned out to be much cheaper than predicted.

The best economic experts have validated the wisdom of adopting climate policies: from Yale’s William Nordhaus, who has supported moderate carbon taxes to cut emissions as an “insurance policy” against the most serious consequences of climate change, to MIT’s Richard Schmalensee and Columbia’s Glenn Hubbard, who have endorsed the climate policy recommendations of the bipartisan National Commission on Energy Policy, to Harvard’s Martin Weitzman, who has argued for much more aggressive policies because of the risk of particularly catastrophic outcomes. And a diverse set of CEOs, including the heads of some of the largest U.S. corporations, acting as part of the U.S. Climate Action Partnership, have called on the government “to quickly enact strong national legislation to require significant reductions of greenhouse gas emissions.”

Critics are wary of raising energy prices, arguing that no nations have grown wealthy with expensive power. But historically, it is the scarcity and cost of energy that have prompted technological changes as well as the use of new forms of power. What’s more, critics challenge the price estimates the experts have set out. They say that the predictions depend on extensive — and unrealistic — cooperation among nations. In particular, they say, developing nations won’t sign onto plans for curbing emissions, for fear of losing their economic momentum.

Indeed, we do need a sensible international arrangement in place to achieve low costs, and the economic pain will be much greater if we don’t set up an international carbon market. But it can be done. Many nations have already initiated such emissions-control policies. And the world can be brought together in a meaningful, long-term arrangement that is scientifically sound, economically rational and politically pragmatic.

Road to Cooperation

Because the benefits of any single nation taking action to address global climate change are spread worldwide, unlike the costs, it may never be in the self-interest of a single country to take unilateral action. This is the nature of a global commons problem. For this reason, international cooperation is required; this is the point of climate negotiations among some 190 countries, which will continue in Copenhagen this December. It is also the motivation for the U.S. administration’s Major Economies Forum, which brings together the 17 largest economies, accounting for 80% of GHG emissions.

Europe has already put significant climate policy in place, and Australia, New Zealand, and Japan are moving to have their policies in place within a year. But without evidence of serious action by the U.S., there will be no meaningful future international agreement, and certainly not one that includes the key, rapidly-growing developing countries — Brazil, China, India, Indonesia, Mexico, South Africa, and South Korea. U.S. policy developments can and should move in parallel with international negotiations.

Understandably, developing countries have a very different perspective than the currently industrialized world regarding climate policy. After all, the vast majority of the accumulated stock of man-made greenhouse gases in the atmosphere is due to economic activity in the richer countries over the past century and more. But the share of global emissions attributable to developing countries is significant and growing rapidly. China surpassed the United States as the world’s largest CO2 emitter in 2006. And developing countries are likely to account for more than half of global emissions by the year 2020, if not before. China, Korea, and others are beginning to take action.

Most important, all of the key countries of the world can be brought together in a meaningful and pragmatic arrangement. Such a post-Kyoto international agreement can expand the scope of action to include key developing countries, but with targets linked via an appropriate formula with economic growth, so that emissions can be reduced around the world, while emissions (and job) leakage from the industrialized to the developing world is avoided, and economic growth continues in all parts of the world.

Reducing Costs

The longer we put off serious action, the more aggressive our future efforts will need to be, as greenhouse gases and carbon-spewing capital assets continue to accumulate. Plants built today will determine emissions for a generation. In the steel sector — where plant lifetimes typically exceed 25 years — more than half of all plants in the world are now less than 10 years old. The picture is similar in the cement industry, as well as more broadly throughout the economy. For every year of delay before moving to a sustainable emissions path, the global cost of taking necessary actions increases by hundreds of billions of dollars.

Critics argue that we can afford to wait because the world of tomorrow will be wealthier and better able to absorb the costs. But acting sooner, such as by adopting the emission caps proposed in the U.S. House legislation, will lower the ultimate costs of achieving the target, because there will be more time allowed for gradual transition — which is what keeps costs down. Perhaps most important, the costs of failing to take action — the damages of climate change — would be substantially greater.

Getting serious about climate change won’t be free, and it won’t be easy. But if state-of-the-science predictions about the consequences of continued delay are correct, the time has come for sensible and meaningful action.

Too Good to be True?

Global climate change is a serious environmental threat, and sound public policies are needed to address it effectively and sensibly.

There is now significant interest and activity within both the U.S. Administration and the U.S. Congress to develop a meaningful national climate policy in this country.  (If you’re interested, please see some of my previous posts:  “Opportunity for a Defining Moment” (February 6, 2009); “The Wonderful Politics of Cap-and-Trade:  A Closer Look at Waxman-Markey” (May 27, 2009); “Worried About International Competitiveness?  Another Look at the Waxman-Markey Cap-and-Trade Proposal” (June 18, 2009); “National Climate Change Policy:  A Quick Look Back at Waxman-Markey and the Road Ahead” (June 29, 2009).  For a more detailed account, see my Hamilton Project paper, A U.S. Cap-and-Trade System to Address Global Climate Change.)

And as we move toward the international negotiations to take place in December of this year in Copenhagen, it is important to keep in mind the global commons nature of the problem, and hence the necessity of designing and implementing an international policy architecture that is scientifically sound, economically rational, and politically pragmatic.

Back in the U.S., with domestic action delayed in the Senate, several states and regions in the United States have moved ahead with their own policies and plans.  Key among these is California’s Global Warming Solutions Act of 2006, intended to return the state’s greenhouse gas (GHG) emissions in 2020 to their 1990 level.  In 2006, three studies were released indicating that California can meet its 2020 target at no net economic cost.  That is not a typographical error.  The studies found not simply that the costs will be low, but that the costs will be zero, or even negative!  That is, the studies found that California’s ambitious target can be achieved through measures whose direct costs would be outweighed by offsetting savings they create, making them economically beneficial even without considering the emission reductions they may achieve.  Not just a free lunch, but a lunch we are paid to eat!

Given the substantial emission reductions that will be required to meet California’s 2020 target, these findings are ­- to put it mildly – surprising, and they differ dramatically from the vast majority of economic analyses of the cost of reducing GHG emissions.  As a result, I was asked by the Electric Power Research Institute – along with my colleagues, Judson Jaffe and Todd Schatzki of Analysis Group – to evaluate the three California studies.

In a report titled, “Too Good To Be True?  An Examination of Three Economic Assessments of California Climate Change Policy,” we found that although some limited opportunities may exist for no-cost emission reductions, the studies substantially underestimated the cost of meeting California’s 2020 target — by omitting important components of the costs of emission reduction efforts, and by overestimating offsetting savings some of those efforts yield through improved energy efficiency.  In some cases, the studies focused on the costs of particular actions to reduce emissions, but failed to consider the effectiveness and costs of policies that would be necessary to bring about those actions.  Just a few of the flaws we identified lead to underestimation of annual costs on the order of billions of dollars.  Sadly, the studies therefore did not and do not offer reliable estimates of the cost of meeting California’s 2020 target.

This episode is a reminder of a period when similar studies were performed by the U.S. Department of Energy at the time of the Kyoto Protocol negotiations.  Like the California studies, the DOE (Interlaboratory Work Group) studies in the late 1990s suggested that substantial emission reductions could be achieved at no cost.  Those studies were terribly flawed, which was what led to their faulty conclusions.  I had thought that such arguments about massive “free lunches” in the energy efficiency and climate domain had long since been laid to rest.  The debates in California (and some of the rhetoric in Washington) prove otherwise.

While the Global Warming Solutions Act of 2006 sets an emissions target, critical policy design decisions remain to be made that will fundamentally affect the cost of the policy.  For example, policymakers must determine the emission sources that will be regulated to meet those targets, and the policy instruments that will be employed.  The California studies do not directly address the cost implications of these and other policy design decisions, and their overly optimistic findings may leave policymakers with an inadequate appreciation of the stakes associated with the decisions that lie ahead.

On the positive side, a careful evaluation of the California studies highlights some important policy design lessons that apply regardless of the extent to which no-cost emission reduction opportunities really exist.  Policies should be designed to account for uncertainty regarding emission reduction costs, much of which will not be resolved before policies must be enacted.  Also, consideration of the market failures that lead to excessive GHG emissions makes clear that to reduce emissions cost-effectively, policymakers should employ a market-based policy (such as cap-and-trade) as the core policy instrument.

The fact that the three California studies so egregiously underestimated the costs of achieving the goals of the Global Warming Solutions Act should not be taken as indicating that the Act itself is necessarily without merit.  As I have discussed in previous posts, that judgment must rest – from an economic perspective – on an honest and rigorous comparison of the Act’s real benefits and real costs.

Is Benefit-Cost Analysis Helpful for Environmental Regulation?

With the locus of action on Federal climate policy moving this week from the House of Representatives to the Senate, this is a convenient moment to step back from the political fray and reflect on some fundamental questions about U.S. environmental policy.

One such question is whether economic analysis – in particular, the comparison of the benefits and costs of proposed policies – plays a truly useful role in Washington, or is it little more than a distraction of attention from more important perspectives on public policy, or – worst of all – is it counter-productive, even antithetical, to the development, assessment, and implementation of sound policy in the environmental, resource, and energy realms.   With an exceptionally talented group of thinkers – including scientists, lawyers, and economists – now in key environmental and energy policy positions at the White House, the Environmental Protection Agency, the Department of Energy, and the Department of the Treasury, this question about the usefulness of benefit-cost analysis is of particular importance.

For many years, there have been calls from some quarters for greater reliance on the use of economic analysis in the development and evaluation of environmental regulations.  As I have noted in previous posts on this blog, most economists would argue that economic efficiency — measured as the difference between benefits and costs — ought to be one of the key criteria for evaluating proposed regulations.  (See:  “The Myths of Market Prices and Efficiency,” March 3, 2009; “What Baseball Can Teach Policymakers,” April 20, 2009; “Does Economic Analysis Shortchange the Future?” April 27, 2009)  Because society has limited resources to spend on regulation, such analysis can help illuminate the trade-offs involved in making different kinds of social investments.  In this sense, it would seem irresponsible not to conduct such analyses, since they can inform decisions about how scarce resources can be put to the greatest social good.

In principle, benefit-cost analysis can also help answer questions of how much regulation is enough.  From an efficiency standpoint, the answer to this question is simple — regulate until the incremental benefits from regulation are just offset by the incremental costs.  In practice, however, the problem is much more difficult, in large part because of inherent problems in measuring marginal benefits and costs.  In addition, concerns about fairness and process may be very important economic and non-economic factors.  Regulatory policies inevitably involve winners and losers, even when aggregate benefits exceed aggregate costs.

Over the years, policy makers have sent mixed signals regarding the use of benefit-cost analysis in policy evaluation.  Congress has passed several statutes to protect health, safety, and the environment that effectively preclude the consideration of benefits and costs in the development of certain regulations, even though other statutes actually require the use of benefit-cost analysis.  At the same time, Presidents Carter, Reagan, Bush, Clinton, and Bush all put in place formal processes for reviewing economic implications of major environmental, health, and safety regulations. Apparently the Executive Branch, charged with designing and implementing regulations, has seen a greater need than the Congress to develop a yardstick against which regulatory proposals can be assessed.  Benefit-cost analysis has been the yardstick of choice

It was in this context that ten years ago a group of economists from across the political spectrum jointly authored an article in Science magazine, asking whether there is role for benefit-cost analysis in environmental, health, and safety regulation.  That diverse group consisted of Kenneth Arrow, Maureen Cropper, George Eads, Robert Hahn, Lester Lave, Roger Noll, Paul Portney, Milton Russell, Richard Schmalensee, Kerry Smith, and myself.  That article and its findings are particularly timely, with President Obama considering putting in place a new Executive Order on Regulatory Review.

In the article, we suggested that benefit-cost analysis has a potentially important role to play in helping inform regulatory decision making, though it should not be the sole basis for such decision making.  We offered eight principles.

First, benefit-cost analysis can be useful for comparing the favorable and unfavorable effects of policies, because it can help decision makers better understand the implications of decisions by identifying and, where appropriate, quantifying the favorable and unfavorable consequences of a proposed policy change.  But, in some cases, there is too much uncertainty to use benefit-cost analysis to conclude that the benefits of a decision will exceed or fall short of its costs.

Second, decision makers should not be precluded from considering the economic costs and benefits of different policies in the development of regulations.  Removing statutory prohibitions on the balancing of benefits and costs can help promote more efficient and effective regulation.

Third, benefit-cost analysis should be required for all major regulatory decisions. The scale of a benefit-cost analysis should depend on both the stakes involved and the likelihood that the resulting information will affect the ultimate decision.

Fourth, although agencies should be required to conduct benefit-cost analyses for major decisions, and to explain why they have selected actions for which reliable evidence indicates that expected benefits are significantly less than expected costs, those agencies should not be bound by strict benefit-cost tests.  Factors other than aggregate economic benefits and costs may be important.

Fifth, benefits and costs of proposed policies should be quantified wherever possible.  But not all impacts can be quantified, let alone monetized.  Therefore, care should be taken to assure that quantitative factors do not dominate important qualitative factors in decision making.  If an agency wishes to introduce a “margin of safety” into a decision, it should do so explicitly.

Sixth, the more external review that regulatory analyses receive, the better they are likely to be.  Retrospective assessments should be carried out periodically.

Seventh, a consistent set of economic assumptions should be used in calculating benefits and costs.  Key variables include the social discount rate, the value of reducing risks of premature death and accidents, and the values associated with other improvements in health.

Eighth, while benefit-cost analysis focuses primarily on the overall relationship between benefits and costs, a good analysis will also identify important distributional consequences for important subgroups of the population.

From these eight principles, we concluded that benefit-cost analysis can play an important role in legislative and regulatory policy debates on protecting and improving the natural environment, health, and safety.  Although formal benefit-cost analysis should not be viewed as either necessary or sufficient for designing sensible public policy, it can provide an exceptionally useful framework for consistently organizing disparate information, and in this way, it can greatly improve the process and hence the outcome of policy analysis.

If properly done, benefit-cost analysis can be of great help to agencies participating in the development of environmental regulations, and it can likewise be useful in evaluating agency decision making and in shaping new laws (which brings us full-circle to the climate legislation that will be developed in the U.S. Senate over the weeks and months ahead, and which I hope to discuss in future posts).

Does economic analysis shortchange the future?

Decisions made today usually have impacts both now and in the future. In the environmental realm, many of the future impacts are benefits, and such future benefits — as well as costs — are typically discounted by economists in their analyses.  Why do economists do this, and does it give insufficient weight to future benefits and thus to the well-being of future generations?

This is a question my colleague, Lawrence Goulder, a professor of economics at Stanford University, and I addressed in an article in Nature.  We noted that as economists, we often encounter skepticism about discounting, especially from non-economists. Some of the skepticism seems quite valid, yet some reflects misconceptions about the nature and purposes of discounting.  In this post, I hope to clarify the concept and the practice.

It helps to begin with the use of discounting in private investments, where the rationale stems from the fact that capital is productive ­– money earns interest.  Consider a company trying to decide whether to invest $1 million in the purchase of a copper mine, and suppose that the most profitable strategy involves extracting the available copper 3 years from now, yielding revenues (net of extraction costs) of $1,150,000. Would investing in this mine make sense?  Assume the company has the alternative of putting the $1 million in the bank at 5 per cent annual interest. Then, on a purely financial basis, the company would do better by putting the money in the bank, as it will have $1,000,000 x (1.05)3, or $1,157,625, that is, $7,625 more than it would earn from the copper mine investment.

I compared the alternatives by compounding to the future the up-front cost of the project. It is mathematically equivalent to compare the options by discounting to the present the future revenues or benefits from the copper mine. The discounted revenue is $1,150,000 divided by (1.05)3, or $993,413, which is less than the cost of the investment ($1 million).  So the project would not earn as much as the alternative of putting the money in the bank.

Discounting translates future dollars into equivalent current dollars; it undoes the effects of compound interest. It is not aimed at accounting for inflation, as even if there were no inflation, it would still be necessary to discount future revenues to account for the fact that a dollar today translates (via compound interest) into more dollars in the future.

Can this same kind of thinking be applied to investments made by the public sector?  Since my purpose is to clarify a few key issues in the starkest terms, I will use a highly stylized example that abstracts from many of the subtleties.  Suppose that a policy, if introduced today and maintained, would avoid significant damage to the environment and human welfare 100 years from now. The ‘return on investment’ is avoided future damages to the environment and people’s well-being. Suppose that this policy costs $4 billion to implement, and that this cost is completely borne today.  It is anticipated that the benefits – avoided damages to the environment – will be worth $800 billion to people alive 100 years from now.  Should the policy be implemented?

If we adopt the economic efficiency criterion I have described in previous posts, the question becomes whether the future benefits are large enough so that the winners could potentially compensate the losers and still be no worse off?  Here discounting is helpful. If, over the next 100 years, the average rate of interest on ordinary investments is 5 per cent, the gains of $800 billion to people 100 years from now are equivalent to $6.08 billion today.  Equivalently, $6.08 billion today, compounded at an annual interest rate of 5 per cent, will become $800 billion in 100 years. The project satisfies the principle of efficiency if it costs current generations less than $6.08 billion, otherwise not.

Since the $4 billion of up-front costs are less than $6.08 billion, the benefits to future generations are more than enough to offset the costs to current generations. Discounting serves the purpose of converting costs and benefits from various periods into equivalent dollars of some given period.  Applying a discount rate is not giving less weight to future generations’ welfare.  Rather, it is simply converting the (full) impacts that occur at different points of time into common units.

Much skepticism about discounting and, more broadly, the use of benefit-cost analysis, is connected to uncertainties in estimating future impacts. Consider the difficulties of ascertaining, for example, the benefits that future generations would enjoy from a regulation that protects certain endangered species. Some of the gain to future generations might come in the form of pharmaceutical products derived from the protected species. Such benefits are impossible to predict. Benefits also depend on the values future generations would attach to the protected species – the enjoyment of observing them in the wild or just knowing of their existence. But how can we predict future generations’ values?  Economists and other social scientists try to infer them through surveys and by inferring preferences from individuals’ behavior.  But these approaches are far from perfect, and at best they indicate only the values or tastes of people alive today.

The uncertainties are substantial and unavoidable, but they do not invalidate the use of discounting (or benefit-cost analysis).  They do oblige analysts, however, to assess and acknowledge those uncertainties in their policy assessments, a topic I discussed in my last post (“What Baseball Can Teach Policymakers”), and a topic to which I will return in the future.

What Baseball Can Teach Policymakers

With the Major League Baseball season having just begun, I’m reminded of the truism that the best teams win their divisions in the regular season, but the hot teams win in the post-season playoffs.  Why the difference?  The regular season is 162 games long, but the post-season consists of just a few brief 5-game and 7-game series.  And because of the huge random element that pervades the sport, in a single game (or a short series), the best teams often lose, and the worst teams often win.

The numbers are striking, and bear repeating.  In a typical year, the best teams lose 40 percent of their games, and the worst teams win 40 percent of theirs.  In the extreme, one of the best Major League Baseball teams ever ­- the 1927 New York Yankees – lost 29 percent of their games; and one of the worst teams in history – the 1962 New York Mets – won 25 percent of theirs.  On any given day, anything can happen.  Uncertainty is a fundamental part of the game, and any analysis that fails to recognize this is not only incomplete, but fundamentally flawed.

The same is true of analyses of environmental policies.  Uncertainty is an absolutely fundamental aspect of environmental problems and the policies that are employed to address those problems.  Any analysis that fails to recognize this runs the risk not only of being incomplete, but misleading as well.  Judson Jaffe, formerly at Analysis Group, and I documented this in a study published in Regulation and Governance.

To estimate proposed regulations’ benefits and costs, analysts frequently rely on inputs that are uncertain —  sometimes substantially so.  Such uncertainties in underlying inputs are propagated through analyses, leading to uncertainty in ultimate benefit and cost estimates, which constitute the core of a Regulatory Impact Analysis (RIA), required by Presidential Executive Order for all “economically significant” proposed Federal regulations.

Despite this uncertainty, the most prominently displayed results in RIAs are typically single, apparently precise point estimates of benefits, costs, and net benefits (benefits minus costs), masking uncertainties inherent in their calculation and possibly obscuring tradeoffs among competing policy options.  Historically, efforts to address uncertainty in RIAs have been very limited, but guidance set forth in the U.S. Office of Management and Budget’s (OMB) Circular A‑4 on Regulatory Analysis has the potential to enhance the information provided in RIAs regarding uncertainty in benefit and cost estimates.  Circular A‑4 requires the development of a formal quantitative assessment of uncertainty regarding a regulation’s economic impact if either annual benefits or costs are expected to reach $1 billion.

Over the years, formal quantitative uncertainty assessments — known as Monte Carlo analyses — have become common in a variety of fields, including engineering, finance, and a number of scientific disciplines, as well as in “sabermetrics” (quantitative, especially statistical analysis of professional baseball), but rarely have such methods been employed in RIAs.

The first step in a Monte Carlo analysis involves the development of probability distributions of uncertain inputs to an analysis.  These probability distributions reflect the implications of uncertainty regarding an input for the range of its possible values and the likelihood that each value is the true value.  Once probability distributions of inputs to a benefit‑cost analysis are established, a Monte Carlo analysis is used to simulate the probability distribution of the regulation’s net benefits by carrying out the calculation of benefits and costs thousands, or even millions, of times.  With each iteration of the calculations, new values are randomly drawn from each input’s probability distribution and used in the benefit and/or cost calculations.  Over the course of these iterations, the frequency with which any given value is drawn for a particular input is governed by that input’s probability distribution.  Importantly, any correlations among individual items in the benefit and cost calculations are taken into account.  The resulting set of net benefit estimates characterizes the complete probability distribution of net benefits.

Uncertainty is inevitable in estimates of environmental regulations’ economic impacts, and assessments of the extent and nature of such uncertainty provides important information for policymakers evaluating proposed regulations.  Such information offers a context for interpreting benefit and cost estimates, and can lead to point estimates of regulations= benefits and costs that differ from what would be produced by purely deterministic analyses (that ignore uncertainty).  In addition, these assessments can help establish priorities for research.

Due to the complexity of interactions among uncertainties in inputs to RIAs, an accurate assessment of uncertainty can be gained only through the use of formal quantitative methods, such as Monte Carlo analysis.  Although these methods can offer significant insights, they require only limited additional effort relative to that already expended on RIAs.  Much of the data required for these analyses are already obtained by EPA in their preparation of RIAs; and widely available software allows the execution of Monte Carlo analysis in common spreadsheet programs on a desktop computer.  In a specific application in the Regulation and Governance study, Jaffe and I demonstrate the use and advantages of employing formal quantitative analysis of uncertainty in a review of EPA’s 2004 RIA for its Nonroad Diesel Rule.

Formal quantitative assessments of uncertainty can mark a truly significant step forward in enhancing regulatory analysis under Presidential Executive Orders.  They have the potential to improve substantially our understanding of the impact of environmental regulations, and thereby to lead to more informed policymaking.