Reflecting on Trump’s Record and Anticipating Biden’s Performance

On January 20th, a bit more than two weeks from today, Joe Biden will be sworn in as the 46th President of the United States, along with Kamala Harris as Vice President.  Changes from one U.S. administration to another are always significant, but sometimes the anticipated changes are not dramatic when the same political party retains the White House, although the last time that happened was the transition in 1988 from Ronald Reagan to George H.W. Bush.  That said, I do not recall a transition that has represented anticipated changes – in terms both of style and substance – as great as the transition from President Trump to President-Elect Biden.

            One of the areas – among others – where that is the case is the realm of environmental, energy, and natural resource policy.  And there is no one better qualified to reflect on the environmental record of the Trump administration and the prospects of the forthcoming Biden administration that Richard Revesz, my long-time colleague, co-author, and friend.  He is my guest in the latest episode of my podcast, released today, January 5th, on the day a pair of Senate runoff elections in Georgia are taking place (which will determine which political party controls the Senate for at least the next two years).

            As readers of this blog know, in these podcasts – “Environmental Insights: Discussions on Policy and Practice from the Harvard Environmental Economics Program – I talk with well-informed people from academia, government, industry, and NGOs.  Ricky fits the bill as the Lawrence King Professor of Law at New York University, where he was previously Dean, and was the co-founder of the Institute for Policy Integrity.  He is also the co-author with Michael Livermore of a new and important book, Reviving Rationality: Saving Cost-Benefit Analysis for the Sake of the Environment and Our Health.

            You can hear our complete conversation in the Podcast here.

First of all, reflecting on the past four years of the Trump Administration, Revesz points to the decisions to:  roll back motor vehicle energy efficiency (or CAFE) standards; repeal the Obama Administration’s Clean Power Plan; and pursue what the Trump administration termed “strengthening” regulation – all as examples of bad policies with negative consequences.

“On virtually any significant environmental issue, the Trump Administration was on the wrong side. It was on the wrong side of the legal issues; it was in the wrong side of the economic issues; it was in the wrong side of the scientific issues. And it was really on the wrong side of history,” he remarks.  Revesz also implies that the administration’s disrespect for science and economics might have very deep and injurious impacts on environmental policy going forward. 

However, Revesz expresses optimism that the incoming administration may be able to undo some of the damage done over the past four years.

“I am extremely hopeful and very optimistic that the Biden Administration will restore confidence in science and economics, and that these will be taken as serious analytical frameworks, and not as tools to be bent at will to justify the political preferences of the moment,” he says. “And that is extremely important because I don’t think our country could take another four years of the bending of truth without it having very serious long-term repercussions.”

Revesz also says he expects the Biden-Harris Administration to hold true on its campaign promises to push forward with tough greenhouse gas emission policies. 

“I expect we’ll see a continued significant ratcheting down of automobile emissions, including much greater penetration of zero emitting vehicles.  And we will see very significant work, I assume and hope, on the stationary source side. Even in the Obama Administration, where we ended up with regulations for new oil and gas facilities, we didn’t have regulations for existing facilities, which is where a lot of the emissions are. The electric sector will have to be looked at. And then other industrial sectors that have not yet been being gotten attention, like refinery cement plants, will need to get significant attention. So, I see a lot happening on the regulatory side.”

Despite the challenges the Biden-Harris Administration may face from legal challenges to new regulatory actions because of the 220 judges appointed by President Trump as well as the new 6-3 conservative majority in the Supreme Court, Ricky Revesz maintains that the new administration will be much more successful in defending its regulatory actions in the courts than was the Trump administration, which lost an astonishingly high 83 percent of challenges against its regulatory actions.

All of this and more is found in the latest episode of “Environmental Insights: Discussions on Policy and Practice from the Harvard Environmental Economics Program.”  I hope you will listen to this latest discussion here.  You can find a complete transcript of our conversation at the website of the Harvard Environmental Economics Program.

My conversation with Professor Revesz is the 19th episode in the Environmental Insights series, with future episodes scheduled to drop each month.  Previous episodes have featured conversations with:

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


Fifty Years of Policy Evolution under the Clean Air Act

Fifty years ago, in 1970, the first Earth Day was celebrated, the U.S. Environmental Protection Agency (EPA) was established, and the U.S. Clean Air Act was passed.  Much has transpired with air pollution policy in the United States since that time.  Given the current state of Federal clean air policy in this country, it may be helpful to reflect on these fifty years of policy evolution, which is what Richard Schmalensee (of the MIT Sloan School of Management) and I do in a new article that appears in the Journal of Economic Perspectives (Volume 33, Issue 4, Fall 2019), “Policy Evolution under the Clean Air Act.”  I hope this brief essay will stimulate you to download and read the full article.

Setting the Stage

In the article, Professor Schmalensee and I review and assess the evolution of air pollution control policy under the Clean Air Act with particular attention to the types of policy instruments used.  After outlining key provisions of the 1970 act and its main changes over time, we trace and assess the historical evolution of the policy instruments used by EPA in its clean air regulations.  This evolution was sometimes driven by the emergence of new air quality problems, sometimes by innovation and experimentation within EPA, and sometimes by changes in the Clean Air Act itself.

It is striking that until about 2000, EPA made increasing use of market-based instruments, enabled by major amendments to the Act in 1977 and 1990, which passed with overwhelming bipartisan support. In recent years, however, environmental policy has become a partisan battleground in the United States, and until now, it has not been possible to provide an effective response to climate change or to address other new and evolving air quality problems.

Policy Instruments Used under the Clean Air Act

Three major types of policy instruments have been employed under the authority of the Clean Air Act:  technology standards, which specify the equipment or process to be used for compliance; performance standards, which specify the maximum quantity of emissions or maximum atmospheric concentrations that are allowed; and emissions trading systems, either in the form of emissions-reduction credit (offset) systems or cap-and-trade. In addition, taxes have sometimes been employed, although their use under the Clean Air Act has been peripheral.

The Evolution of Air Quality Policy Instruments

Under the 1970 Clean Air Act, all federal air pollution regulation involved either technology standards or performance standards.  At that time, some environmental advocates argued that facilitating greater flexibility through tradable emission rights would inappropriately legitimize environmental degradation, while others questioned the very feasibility of such an approach.  But over time, as the Clean Air Act was amended and as its interpretation by EPA evolved, air pollution regulation evolved from sole reliance on conventional, command-and-control regulations to greater use of emissions trading.

In the article, we examine EPA’s early experiments with emissions trading in the 1970s, and then turn to the leaded gasoline phasedown in the 1980s, implemented via a tradable performance standard by the Reagan administration.  We also take a look at the U.S. approach to complying with the Montreal Protocol for stratospheric ozone protection, which involved both an excise tax and a trading system.

Next up in our review and assessment is the path-breaking sulfur dioxide allowance trading program, under the Clean Air Act amendments of 1990.  We also examine several regional programs that were executed under the authority of the Clean Air Act, including the Regional Clean Air Incentives Market (RECLAIM) in southern California, NOx trading in the eastern United States, and the NOx budget trading program.

To bring this up to date, Dick Schmalensee and I also examine climate change policies, including those of the Obama administration, as well as those of the current, Trump administration.


We conclude that the supporters of the 1970 Clean Air Act, who no doubt hoped that it would produce major environmental benefits, would be pleased that despite the fact that real U.S. GDP more than tripled between 1970 and 2017, aggregate emissions of the six criteria pollutants declined by 73 percent.

On the other hand, the original supporters of the 1970 Clean Air Act might be quite surprised by some aspects of the evolution of clean air regulation under the Act.  For example, it is difficult to imagine that any of the supporters of the 24-page 1970 Act would have predicted how complex air pollution regulation would become over the subsequent half century. And we suspect that the evolution toward more intensive use of market-based environmental policy would also have been a surprise to those involved in passage of the 1970 Clean Air Act.

However, those involved in the bipartisan passage of the 1970 Clean Air Act would likely be disappointed that environmental policy has become a partisan battleground. It has become impossible to amend the Clean Air Act or to pass other legislation to address climate change in a serious and economically sensible manner.

The Path Ahead

In the final part of the article, we note that an implication of these five decades of experience may be that policies to address climate change and other new environmental problems should be designed in ways that make them more acceptable in the real world of politics. This could mean, for example, giving greater attention to suboptimal, second-best designs of carbon-pricing regimes, such as by earmarking revenues from taxes or allowance auctions to finance additional climate mitigation, rather than optimizing the system via cuts in distortionary taxes, or using such revenues for fairness purposes, such as with lump-sum rebates or rebates targeted to low income and other particularly burdened constituencies.

Economists might also be more effective by sometimes working to catch up with the political world by examining better design of second-best non-pricing climate policy instruments, such as clean energy standards, subsidies for green technologies, and other approaches. At some point the politics may change, of course, which is why ongoing economic research on climate policy instruments of all kinds is important.


A Gift that Keeps on Giving: The Contributions of Martin Weitzman to Environmental Economics

The world lost a remarkable scholar, a great economist, and a gentle soul on August 27th, when Martin Weitzman sadly passed away.

A week later, I was asked by the editors of the VOX CEPR Policy Portal (of the Centre for Economic Policy Research) – “research-based policy analysis and commentary from leading economists” ­– to write a brief intellectual biography and personal remembrance of Marty Weitzman, my colleague, friend, and long-time co-host of the Harvard Seminar on Environmental Economics and Policy.  In the essay I wrote, I sought to describe how Marty’s contributions have advanced the thinking of environmental and other economists, as well as the thoughts and actions of policymakers on many fundamental issues, including policy instrument choice, discounting, species diversity, and environmental catastrophes.  Today, I’m offering readers of this blog a slightly edited version of my Vox essay.

Photo Credit: Gernot Wagner

Martin Weitzman was a treasure – a gift that kept on giving to the research and policy worlds – for Harvard, for economists around the world, and for the global intellectual community. His work as an economic theorist who addressed a broad set of problems, and as an environmental economist who during the past decade focused on climate change, was unparalleled, and formed the basis for theoretical and empirical work carried out by legions of economists and other scholars around the world. His contributions to environmental economics in particular were unprecedented, and helped to shape the field for nearly five decades.

If economic theory is about stripping a problem down to its absolute essentials, and deriving meaningful insights from those essentials, then Weitzman was a master. Over and over again, Marty Weitzman demonstrated how careful and rigorous analysis of artfully constructed theoretical models can provide valuable and often surprising insights into difficult economic problems with real implications for the design of public policies.

Marty’s contributions have advanced the thinking of environmental economists and policymakers on policy instrument choice, discounting, species diversity, environmental catastrophes, and other fundamental issues. Across the board, the example of his rigorous and often ingenious work set high standards for theorizing in environmental economics and thereby served to elevate the entire field.

Brief intellectual biography

Born in New York City in 1942, Marty received his BA degree in mathematics and physics from Swarthmore College in 1963, and one year later, received an MS degree in statistics and operations research from Stanford University. In 1967, just three years after his Stanford degree, he was awarded a PhD degree in economics from the Massachusetts Institute of Technology (MIT), where his dissertation committee chair was Bob Solow. From 1967 to 1972, he taught in the Department of Economics at Yale University, then moved to MIT, where he taught in the Department of Economics until 1989, when he moved to Harvard University. He was a Professor of Economics at Harvard until 2018, when he became a Research Professor of Economics.

Economic planning

At the start of his research career, Weitzman studied centrally planned economies in a field that has all but disappeared from academic economics – comparative economic systems. It was during this early period of his career that Marty’s papers with titles such as ‘Soviet Postwar Economic Growth and Capital Labor Substitution’ (1970b) and ‘Iterative Multi-Level Planning with Production Targets’ (1970a) appeared.

A remarkable product of his interest in how to manage a centrally planned economy efficiently was Marty’s classic paper on ‘Prices vs. Quantities’ (1974). He began this work to address the question of whether prices or production quotas would lead to more efficient outcomes in a centrally planned economy (under conditions of uncertainty), but the paper and the subsequent literature evolved to address the question of whether a price instrument or a quantity instrument will be more efficient for environmental regulation.

Although Marty began his first forays into research and writing on environmental and natural resource problems in the 1970s (some of it developing Marxian views of common property problems), it was not until the 1990s that he turned with such passion and energy to this realm, and produced one important work after another that virtually span the field. That outpouring coincided with the beginning of my collaboration with Marty, co-hosting the Harvard Seminar on Environmental Economics and Policy (more on this below).

The share economy

Along the way, Weitzman carried out important research in macroeconomics and unemployment theory. One product of this – along with dozens of journal articles (inevitably in the top periodicals) – was his best-selling 1984 book, The Share Economy – which was eventually translated into seven languages. In this brief (167-page) book, Marty laid out his proposal for how the US economy could be protected from the dual threats of unemployment and inflation with a remarkably simple idea (a hallmark of many of his contributions) – namely that instead of companies paying workers in manufacturing a fixed wage, they be paid through something akin to profit sharing, in particular by paying workers a significant share of company revenue.

In short, this would provide incentives for companies to continue adding workers as long as, through their work, they added to company revenues. This ‘novel, seemingly workable plan for equipping the economy to resist the instabilities’ that had plagued it for more than a decade (Passell 1984), was labelled in the headline of a lead New York Times 1985 editorial, ‘the best idea since Keynes’.

Policy instrument choice: prices versus quantities

For environmental economists, Marty’s most prominent contribution is probably his classic 1974 article, ‘Prices vs. Quantities’, which developed the simultaneously simple and powerful insight that – under conditions of uncertainty – the expected relative efficiency of policy instruments based on prices (such as a pollution tax) versus those based on quantities (such as a cap-and-trade system) depends on the relative slopes of the expected marginal benefit and marginal cost functions.

That work remains one of the most frequently cited articles in all of environmental economics. It stimulated a massive literature, a fact that prompted Richard Newell (Resources for the Future) to characterize the work as a ‘gift that keeps on giving’ at a symposium we held at Harvard in October 2018 to mark Marty’s retirement and celebrate his contributions, ‘Frontiers in Environmental Economics and Policy: A Symposium in Honor of Martin L Weitzman’. Even now, Marty’s 1974 paper is at the core of analysis of carbon taxes versus carbon cap-and-trade systems to address climate change (Karp and Traeger 2018; Mideksa and Weitzman 2019; Stavins 2019).

Colleagues who spoke at the celebration of Marty’s work on October 11, 2018, at the Harvard Kennedy School, “Frontiers in Environmental Economics and Policy: A Symposium in Honor of Martin L. Weitzman.” Front Row, left to right: Michael Greenstone, University of Chicago; Maureen Cropper, University of Maryland; Martin L. Weitzman, Harvard University; Robert Pindyck, Massachusetts Institute of Technology; William Nordhaus, Yale University. Back Row, left to right: James Stock, Harvard University; Charles Kolstad, Stanford University; Lawrence Goulder, Stanford University; Robert Stavins, Harvard University; Richard Newell, Resources for the Future. Photo Credit: Martha Stewart


In the early 1990s, Weitzman responded to what he sensed might be the unwillingness – or the inability – of ecologists to rank ecologies in terms of their relative biodiversity, by producing a series of brilliant treatments of how these comparisons can be made quantitatively and rigorously: ‘On Diversity’ (1992); ‘What to Preserve: An Application of Diversity Theory to Crane Conservation’ (1993); ‘Patterns of Behavior in Biodiversity Preservation’ (Metrick and Weitzman 1996); and ‘The Noah’s Ark Problem’ (1998a). At the Harvard symposium, Charlie Kolstad (Stanford University) cited this body of work for its ‘significance and importance’.


It was also in the 1990s that Marty became interested in a central issue of the economic analysis of climate change policies, namely long-term discounting. Given the long time horizons of the climate change problem, analysis of the expected net present value of alternative policies can be dominated by the choice of discount rate, which – with conventional exponential discounting – will greatly diminish the relative quantitative importance of phenomena that are decades or longer in the future.

Through careful theoretical analysis, Marty concluded that rather than a constant discount rate being employed, a rate that itself is diminishing over time is appropriate, so that benefits and costs in the near future would be subject to a typical rate, while benefits and costs further in the future would be subject to a much lower rate.

This important and influential work appeared in a series of articles, including: ‘On the Environmental Discount Rate’ (1994); ‘Why the Far-Distant Future Should be Discounted at its Lowest Possible Rate’ (1998b); and ‘Gamma Discounting’ (2001a). At the Harvard symposium, Larry Goulder (Stanford University) emphasized that this work is important ‘because it affects decisions as to how much we should invest in infrastructure, in mitigation, and in other realms.’

Green national accounting

A topic that has pervaded decades of analysis and commentary in the environmental sphere is the reality that conventional measures of economic growth, such as gross domestic product, are not measures of welfare, since they do not account for externalities (among other non-market economic phenomena). In 1999, the National Research Council published Nature’s Numbers: Expanding the National Economic Accounts to Include the Environment, produced by a committee chaired by Bill Nordhaus and including Marty Weitzman (Nordhaus and Kokkelenberg 1999). That was linked with several contributions that Weitzman subsequently made to the scholarly literature, including: ‘Does NNP Growth Indicate Welfare Improvement’ (Asheim and Weitzman 2001); and ‘A Contribution to the Theory of Welfare Accounting’ (2001b).

At the Harvard symposium, Bill Nordhaus emphasized Marty’s contributions in this realm, and launched his keynote presentation, ‘The Intellectual Footprint of Martin Weitzman in Environmental Economics’, by stating that Marty ‘has changed the way we think about economics and the environment.’ He concluded that ‘those who claim that environmental regulations hurt growth are completely wrong, because they are using the wrong yardstick. Pollution should be in our measures of national output, but with a negative sign, and if we use green national output as our standard, then environmental and safety regulations have increased true economic growth substantially in recent years… For this important insight we applaud Martin Weitzman, a radically innovative spirit in economics.’


Some will be surprised to learn that a theorist such as Marty Weitzman was as immersed as he was in concerns about the real world of natural resource management and environmental protection. One example comes from his research and outreach in the realm of fisheries management. His modelling of Icelandic commercial fisheries affected thinking and discussion around the world regarding the use of taxes and quotas to regulate open-access fisheries.

As Maureen Cropper (University of Maryland) said at the Harvard symposium, ‘this is another example of the use of a simple model and treatment of uncertainty that really did start a conversation among fisheries economists’. This application of Weitzman’s previously developed theory of instrument choice was documented in his 2002 paper ‘Landing Fees vs Harvest Quotas with Uncertain Fish Stocks’.

Fat tails

In recent years, Marty made prominent and important contributions to thinking about long-term climate change policy with his development of a theory of how positive biophysical feedback loops could lead to uncertainty about the damages of climate change that is best characterized by a probability distribution of damages with fat tails, such as a Pareto distribution, rather than a conventional Gaussian (normal) distribution. The result is greater weight being given to catastrophic (but relatively small probability) outcomes.

Speaking at the Harvard symposium, Bob Pindyck of MIT pointed to Weitzman’s prescient 2007 paper, ‘Subjective Expectations and Asset-Return Puzzles’ as having had a profound influence on Marty’s subsequent modelling of catastrophic climate change. A small subset of the papers Marty published on this topic include: ‘On Modeling and Interpreting the Economics of Catastrophic Climate Change’ (2009); ‘Fat-Tailed Uncertainty in the Economics of Climate Change’ (2011); and ‘Fat Tails and the Social Cost of Carbon’ (2014b).

Domestic and international climate change policy

Marty Weitzman always searched for topics for his research that were not only interesting, but also relevant and important for real-world applications. His recent work exploring alternative policy instruments to address climate change and his critical examinations of the form of international climate agreements provide telling examples of this. It was in this regard that Jim Stock (Harvard University) credited Weitzman for the ‘tremendous influence’ his ideas have had on the formulation of public policy around the world.

Just a few of the many papers that could be cited in this context are: ‘Can Negotiating a Uniform Carbon Price help to Internalize the Global Warming Externality’ (2014a); ‘A Voting Architecture for the Governance of Free-Driver Externalities, with Application to Geoengineering’ (2015); and ‘On a World Climate Assembly and the Social Cost of Carbon’ (2017). Also, of course, Marty and his former student, Gernot Wagner, wrote a lucid and compelling book, Climate Shock: The Economic Consequences of a Hotter Planet (2015).

Theoretical foundations for empirical analyses

It should be emphasized that Marty Weitzman’s theoretical work was not only important for other theorists, but also for empirical economists. In many of the realms described above, his insights were fundamental as the foundation for sound empirical analysis. As Michael Greenstone (University of Chicago) noted at the Harvard symposium, Marty’s work ‘takes something you are kind of confused about, and then after you read it, you can’t understand how in the world you were confused beforehand. It just clarifies things in a way that is really beautiful.’

A remarkable scholar

Marty Weitzman was thus a real treasure – a ‘gift that kept on giving’ – for both the research and policy worlds. His work as a theorist on environment broadly and on climate change in particular was unparalleled, and formed the basis of much theoretical and empirical research carried out by others over several decades. His work – from examining price versus quantity instruments in the early 1970s through his examinations in the last few years of the implications of fat tails in the probability distribution of possible climate damages – have changed the way economists and others think about the environment and policies to protect it.

His contributions were well recognized. He was elected a Fellow of the Econometric Society in 1976; a Fellow of the American Academy of Arts and Sciences in 1986; three times won the annual award for ‘Publication of Enduring Quality’ from the Association of Environmental and Resource Economists; received the 20th Anniversary Prize from Fondazione Eni Enrico Mattei, the Leontief Prize, and the Eric Kempe Prize in 2011; and the John Kenneth Galbraith Award in 2013.


My greatest personal remembrance will be that I learned an immense amount from Marty by co-hosting with him for 26 years the Harvard Seminar on Environmental Economics and Policy. That’s 52 semesters involving more than 400 seminars, each with a distinct paper and presentation by a leading scholar from across the United States and around the world. I found that Marty’s questions and comments were often as insightful as the speaker’s presentation.

Of course, we did not always agree. I remember our spirited discussions contrasting Marty’s strong view of the superiority of carbon taxes and my view of the relative symmetry of price and quantity instruments for climate change. Also we had some long discussions about the 2015 Paris Agreement on climate change, which Marty saw (accurately) for what it lacks, and I saw for its improvements over the international policy architecture that had preceded it. We disagreed, but were never disagreeable (and I never succeeded in changing his mind!). All in all, for three decades, I consistently learned from this remarkable scholar. He truly was a gift that kept on giving.

Marty receiving from the author a book of testimonials by 100 scholars around the world at the celebration of Marty’s work on October 11, 2018, at the Harvard Kennedy School, “Frontiers in Environmental Economics and Policy: A Symposium in Honor of Martin L. Weitzman.” Photo Credit: Martha Stewart


Asheim, Geir B, and Martin L Weitzman (2001), ‘Does NNP Growth Indicate Welfare Improvement?’ Economic Letters 73(2): 233-39.

Karp, Larry, and Christian Traeger (2018), ‘Prices versus Quantities Reassessed’, CESifo Working Paper No. 7331.

Metrick, Andrew, and Martin L Weitzman (1996), ‘Patterns of Behavior in Endangered Species Preservation’, Land Economics 72(1): 1-16.

Mideksa Torben, and Martin L Weitzman (2019), ‘Prices versus Quantities across Jurisdictions’, Journal of the Association of Environmental and Resource Economists 6(5): 883-891.

New York Times (1985), ‘Best Idea Since Keynes’, Editorial, March 28, Section A, page 30.

Nordhaus, William D, and Edward C Kokkelenberg, editors (1999), Nature’s Numbers: Expanding the National Economic Accounts to Include the Environment, Panel on Integrated Environmental and Economic Accounting, National Academy Press.

Nordhaus, William D (2019), ‘The Intellectual Footprint of Martin Weitzman in Environmental Economics’, presentation at ‘Frontiers in Environmental Economics and Policy: A Symposium in Honor of Martin L. Weitzman’, Harvard Kennedy School, October 11.

Passell, Peter (1984), ‘The Editorial Notebook: The Hidden Boon in Profit-Sharing’, New York Times, November 15, Section A, Page 30.

Stavins, Robert N (2019), ‘The Future of U.S. Carbon-Pricing Policy’, NBER Working Paper No. 25912 (

Wagner, Gernot, and Martin L Weitzman (2015), Climate Shock: The Economic Consequences of a Hotter Planet, Princeton University Press.

Weitzman, Martin L (1970a), ‘Iterative Multi-Level Planning with Production Targets’, Econometrica 38(1): 50-65.

Weitzman, Martin L (1970b), ‘Soviet Postwar Economic Growth and Capital Labor Substitution’, American Economic Review 60 (4): 676-92.

Weitzman, Martin L (1974), ‘Prices vs. Quantities’, Review of Economic Studies 41(4): 477-91.

Weitzman, Martin L (1984), The Share Economy, Harvard University Press.

Weitzman, Martin L (1992), ‘On Diversity’, Quarterly Journal of Economics 107(2): 363-405.

Weitzman, Martin L (1993), ‘What to Preserve: An Application of Diversity Theory to Crane Conservation’, Quarterly Journal of Economics 108(1): 157-83.

Weitzman, Martin L (1994), ‘On the ‘Environmental’ Discount Rate’, Journal of Environmental Economics and Management 26: 200-9.

Weitzman, Martin L (1998a), ‘The Noah’s Ark Problem’, Econometrica 66(6): 1279-98.

Weitzman, Martin L (1998b), ‘Why the Far-Distant Future Should be Discounted at its Lowest Possible Rate’, Journal of Environmental Economics and Management 36(3): 201-8.

Weitzman, Martin L (2001a), ‘Gamma Discounting’, American Economic Review 91(1): 260-71.

Weitzman, Martin L (2001b), ‘A Contribution to the Theory of Welfare Accounting’, Scandinavian Journal of Economics 103(1): 1-23.

Weitzman, Martin L (2002), ‘Landing Fees vs Harvest Quotas with Uncertain Fish Stocks’, Journal of Environmental Economics and Management 43: 325-38.

Weitzman, Martin L (2007), ‘Subjective Expectations and Asset-Return Puzzles’, American Economic Review 97(4): 1102-30.

Weitzman, Martin L (2009), ‘On Modeling and Interpreting the Economics of Catastrophic Climate Change’, Review of Economics and Statistics 91(1): 1-19.

Weitzman, Martin L (2011), ‘Fat-Tailed Uncertainty in the Economics of Catastrophic Climate Change’, Review of Environmental Economics and Policy 5(2): 275-92.

Weitzman, Martin L (2014a), ‘Can Negotiating a Uniform Carbon Price Help to Internalize the Global Warming Externality?’, Journal of the Association of Environmental and Resource Economists 1(1/2): 29-49.

Weitzman, Martin L (2014b), ‘Fat Tails and the Social Cost of Carbon’, American Economic Review Papers and Proceedings 104(5): 544-6.

Weitzman, Martin L (2015), ‘A Voting Architecture for the Governance of Free-Driver Externalities, with Application to Geoengineering’, Scandinavian Journal of Economics 117(4): 1049-68.

Weitzman, Martin L (2017), ‘On a World Climate Assembly and the Social Cost of Carbon’, Economica 84(336): 559-86.