uncertainty Archives - An Economic View of the Environment

It’s Not Too Soon to Take Climate Change Adaptation Seriously

Much more research, reflection, and policy action have been dedicated to the mitigation of climate change than to adaptation. Both are important, and given the fact that climate change is already taking place and likely to accelerate, it is surely not too soon to begin taking adaptation seriously. This point is made in compelling fashion by Robert Pindyck, the Bank of Tokyo-Mitsubishi Professor of Economics and Finance at MIT’s Sloan School of Management, in the latest episode of our podcast, “Environmental Insights: Discussions on Policy and Practice from the Harvard Environmental Economics Program.” I hope you can find time to listen to our conversation here.

In these podcasts, I converse with leading experts from academia, government, industry, and NGOs. My long-time colleague and friend, Bob Pindyck, fits exceptionally well in this group, as a Fellow of the Econometric Society, a past President and Fellow of the Association of Environmental and Resource Economists, and – I’m pleased to say – an Associate Scholar of the Harvard Environmental Economics Program.

Although Professor Pindyck is well known as an energy economist, his research, writing, and expertise is much broader than that, which makes me think of two of his several books, namely a pair of text books co-authored with Daniel Rubinfeld of the University of California at Berkeley: Econometric Models and Economic Forecasts (which I found immensely helpful during my years in graduate school), andMicroeconomics, an intermediate textbook now in its 9^th edition.

But over the past decade, Pindyck has spent much of his time bringing his expertise to bear on issues related to climate change and climate change policy. In fact, he is the author of the forthcoming book, “Climate Future: Averting and Adapting to Climate Change,” to be published by Oxford University Press. In our podcast conversation, Pindyck notes that his new book speaks to the role of uncertainty in the context of climate policy, both with regard to mitigation and adaptation:

“There is a lot we don’t know about climate change and how the system works. And my interest is what does that mean for policy? What do you do when you don’t know know certain things, when you’re uncertain, when many of the characteristics of the system are uncertain? So that got me interested in this,” he remarks.

“I’m very, very clear in the book that it’s extremely important to reduce emissions and that we have to do everything we can to reduce emissions quickly and as much as possible. But we also have to be realistic about what’s going to happen. Despite our best intentions, the world may not succeed and likely won’t succeed in reducing emissions enough to prevent a temperature increase [of] greater than two degrees. We can’t just make believe that we’re going to be able to do something that in fact we’re not going to do.”

Possibilities and policies for adaptation, Bob Pindyck points out, constitute a relatively new lens through which to view the future of climate change policy.

“What we’d like to do is to sharply reduce CO₂ emissions and prevent a temperature increase of two degrees Celsius, and as I started doing a bunch of calculations, it just became clear to me that, that is very unlikely. And then the question is, what should we do if that’s very unlikely? Just say that’s too bad or what? And I came to the view that we need to start working now on adaptation to get ready for that possibility.”

Professor Pindyck suggests that solar geoengineering is just one example of potential measures that could help mitigate the impacts of climate change. The others, he notes, range from planting of trees to less construction of homes in flood zones.

Pindyck says that academics and policymakers must also focus more urgently on the social cost of carbon, and on defining an equitable discount rate that accurately addresses the costs and benefits that will accrue far into the future.

“This is simply an area where despite many, many years of work on discounting, we really don’t know how to address the issue of discounting climate damages that are going to happen 50 or a hundred years from now. What kind of discount rate do we use? Do we use market rates? Do we use ethical arguments for choosing a discount rate? If so, whose ethics?”

For this and much more, I hope you will listen to my complete conversation with Robert Pindyck, the 29^th episode in the Environmental Insights series, with future episodes scheduled to drop each month. You can find a transcript of our conversation at the website of the Harvard Environmental Economics Program. Previous episodes have featured conversations with:

Gina McCarthy, former Administrator of the U.S. Environmental Protection Agency
Nick Stern of the London School of Economics discussing his career, British politics, and efforts to combat climate change
Andrei Marcu, founder and executive director of the European Roundtable on Climate Change and Sustainable Transition
Paul Watkinson, Chair of the Subsidiary Body for Scientific and Technological Advice (SBSTA) within the United Nations Framework Convention on Climate Change
Jos Delbeke, professor at the European University Institute in Florence and at the KU Leuven in Belgium, and formerly Director-General of the European Commission’s DG Climate Action
David Keith, professor at Harvard and a leading authority on geoengineering
Joe Aldy, professor of the practice of public policy at Harvard Kennedy School, with considerable experience working on climate change policy issues in the U.S. government
Scott Barrett, professor of natural resource economics at Columbia University, and an authority on infectious disease policy
Rebecca Henderson, John and Natty McArthur University Professor at Harvard University, and founding co-director of the Business and Environment Initiative at Harvard Business School.
Sue Biniaz, who was the lead climate lawyer and a lead climate negotiator for the United States from 1989 until early 2017.
Richard Schmalensee, the Howard W. Johnson Professor of Management, and Professor of Economics Emeritus at the Massachusetts Institute of Technology.
Kelley Kizier, Associate Vice President for International Climate at the Environmental Defense Fund.
David Hone, Chief Climate Change Adviser, Shell International.
Vicky Bailey, 30 years of experience in corporate and government positions in the energy sector.
David Victor, professor of international relations at the University of California, San Diego.
Lisa Friedman, reporter on the climate desk at the The New York Times.
Coral Davenport, who covers energy and environmental policy for The New York Times from Washington.
Spencer Dale, BP Group Chief Economist.
Richard Revesz, AnBryce Professor of Law and Dean Emeritus, New York University School of Law.
Daniel Esty, Hillhouse Professor of Environment and Law at Yale University.
William Hogan, Raymond Plank Research Professor of Global Energy Policy at Harvard.
Jody Freeman, Archibald Cox Professor of Law at Harvard Law School.
John Graham, Dean Emeritus, Paul O’Neill School of Public and Environmental Affairs, Indiana University.
Gernot Wagner, Clinical Associate Professor at New York University.
John Holdren, Research Professor, Harvard Kennedy School.
Larry Goulder, Shuzo Nishihara Professor of Environmental and Resource Economics, Stanford University.
Suzi Kerr, Chief Economist, Environmental Defense Fund.
Sheila Olmstead, Professor of Public Affairs, LBJ School of Public Affairs, University of Texas, Austin.

“Environmental Insights” is hosted on SoundCloud, and is also available on iTunes, Pocket Casts, Spotify, and Stitcher.

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.