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


Reflections on Twenty Years of Policy Innovation

In 2009, the U.S. Congress considered but ultimately failed to enact legislation aimed at limiting U.S. greenhouse-gas (GHG) emissions.  The bill under consideration at that time, the American Clean Energy and Security Act of 2009, was the last in a series considered over several years.  Sponsored by Representatives Henry Waxman (D-California) and Edward Markey (D-Massachusetts), the bill passed the U.S. House of Representatives but failed to win sufficient support in the Senate.  No legislation was enacted, and by 2010, both Congress and the White House had abandoned efforts to pass federal climate legislation.

Over months of contentious debate, while the Waxman-Markey bill and subsequent Senate action were being considered, millions of Americans were introduced for the first time to the phrase “cap and trade,” a regulatory approach that first came to prominence in the 1990s as the centerpiece of a national program to address the threat of acid rain by limiting emissions of sulfur dioxide (SO2), primarily from electric power plants.

The 1990 SO2 cap-and-trade program was conceived by the administration of President George H. W. Bush and was widely viewed as a success.  Yet cap and trade became a lightning rod for congressional opposition to climate legislation from 2009 through 2010.

Some of that hostility reflected skepticism about whether climate change was real and, if it was, whether humans played a key role in causing it. A larger group of opponents in Congress worried about the proper role of government and the costs of combating climate change, particularly given the lack of commitments for action by the large emerging economies of China, India, Brazil, Korea, South Africa, and Mexico.  The congressional debate touched only lightly on the relative merits of various policy options to reduce greenhouse-gas emissions. Thus, cap and trade may not have been defeated on its merits (or demerits), but rather as collateral damage in the larger climate policy wars.

Congress (to the extent it did assess policy alternatives to cap and trade), as well as the broader community of analysts and observers in the late 2000s, raised a number of substantive questions about the merits of this policy instrument as a means for responding to a major environmental policy challenge of the sort posed by climate change:

  • How do the costs of a market-based approach, such as cap-and-trade, compare with traditional regulatory policies to reduce pollution?
  • Can market-based policies—and the markets they create—be trusted to reduce emissions? That is, are they environmentally effective?
  • What are the distributional impacts of market-based environmental policies; who are the winners and losers?
  • How well does a cap-and-trade system stimulate technological innovation, as compared with an environmental policy that sets performance standards, specifies technologies for reducing pollution, or both?

In May 2011, the Harvard Environmental Economics Program hosted a two-day research workshop and policy roundtable in Cambridge, Massachusetts, to reflect on these and other questions in light of twenty years of experience implementing the SO2 cap-and-trade program, established under Title IV of the Clean Air Act Amendments (CAAA) of 1990. Also known as the Acid Rain Program and the SO2 allowance-trading system, Title IV represented the first large-scale application of cap and trade to control pollution—in the United States or any other country.  (Of course, the largest emissions trading program in the world is now the European Union Emissions Trading System (EU ETS), a greenhouse-gas, cap-and-trade system that was implemented in 2005 and whose design was influenced by the U.S. SO2 program.)

A “policy brief” synthesizing the main conclusions and insights that emerged from the May 2011 Harvard workshop and roundtable has just been released, The SO2 Allowance Trading System and the Clean Air Act Amendments of 1990:  Reflections on Twenty Years of Policy Innovation.  The workshop and roundtable – sponsored by the Alfred P. Sloan Foundation – featured a dream team of economists and legal experts who had conducted extensive research on the SO2 allowance-trading system, as well as leaders of non-governmental organizations and former government officials who had guided the formulation and passage of the CAAA.

The new policy brief examines the design, enactment, implementation, and performance of the SO2 allowance trading system, with an eye toward identifying lessons learned for future efforts to apply cap and trade to other environmental challenges, including global climate change.  The first section provides background on the acid rain program and summarizes data and analysis on its benefits. Subsequent sections examine key questions regarding cost, environmental effectiveness, market performance, distributional implications, and effects on technology innovation.  The report also examines the political context of the formulation, enactment, and implementation of the SO2 allowance-trading system.  Finally, the conclusions feature some reflection on implications for climate change policy.

The participants in the research workshop were:  Joseph Aldy, Assistant Professor of Public Policy, Harvard Kennedy School; Dallas Burtraw, Darius Gaskins Senior Fellow, Resources for the Future; Denny Ellerman, Part-time Professor, European University Institute, Robert Schuman Centre for Advanced Studies; Michael Greenstone, 3M Professor of Environmental Economics, Massachusetts Institute of Technology; Lawrence H. Goulder, Shuzo Nishihara Professor of Environmental and Resource Economics, Stanford University; Robert Hahn, Director of Economics, Smith School, University of Oxford; Paul L. Joskow, President, Alfred P. Sloan Foundation; Erin T. Mansur, Associate Professor of Economics, Dartmouth College; Albert McGartland, Director, National Center for Environmental Economics, U.S. Environmental Protection Agency; Brian J. McLean, Former Director, Office of Atmospheric Programs, U.S. Environmental Protection Agency; W. David Montgomery, Senior Vice President, NERA Economic Consulting; Erich J. Muehlegger, Associate Professor of Public Policy, Harvard Kennedy School; Karen L. Palmer, Senior Fellow, Resources for the Future; John Parsons, Executive Director, Center for Energy and Environmental Policy Research, MIT Sloan School of Management; Forest L. Reinhardt, John D. Black Professor of Business Administration, Harvard Business School; Richard L. Schmalensee, Howard W. Johnson Professor of Economics and Management, MIT Sloan School of Management; Daniel Schrag, Sturgis Hooper Professor of Geology, Harvard University; Robert N. Stavins, Albert Pratt Professor of Business and Government, Harvard Kennedy School; Thomas Tietenberg, Mitchell Family Professor of Economics, Emeritus, Colby College; and Jonathan B. Wiener, William R. and Thomas L. Perkins Professor of Law, Duke University Law School.

The participants in the policy and politics roundtable were:  Robert Grady, General Partner, Cheyenne Capital Fund (1989–1991: Associate Director, Office of Management and Budget for Natural Resources, Energy & Science; 1991–1993 Executive Associate Director, OMB, and Deputy Assistant to the President); C. Boyden Gray, Principal, Boyden Gray & Associates (1989–1993: White House Counsel); Fred Krupp, President (1984–present), Environmental Defense Fund; Mary D. Nichols, Chairman, California Air Resources Board (1993–1997: Assistant Administrator for Air and Radiation, U.S. Environmental Protection Agency); Roger Porter, IBM Professor of Business and Government, Harvard Kennedy School (1989–1993: Assistant to the President for Economic and Domestic Policy); Richard L. Schmalensee, Howard W. Johnson Professor of Economics and Management, MIT Sloan School of Management (1989–1991: Member, President’s Council of Economic Advisers); and Philip Sharp, President, Resources for the Future (1975–1995: Member, U.S. House of Representatives, Indiana, and Chairman, Energy and Power Subcommittee, House Committee on Natural Resources).

I want to acknowledge the contributions of all of these participants in the research workshop and policy roundtable, as well as the comments and edits some provided on earlier drafts of the policy brief.  Their expertise and experience made this project possible. And, of course, I’m very grateful to the Alfred P. Sloan Foundation for having provided generous support for the workshop and for the preparation of the study.  I hope you find it of interest and value.

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)?