Hamilton Project Archives - An Economic View of the Environment

The Future of U.S. Carbon-Pricing Policy

In 2007, I was asked by the leaders of the Brookings Institution’s Hamilton Project to write a paper describing a national emissions trading system to reduce U.S. carbon dioxide (CO₂) emissions to help address the threat of global climate change. I responded that I would prefer to write broadly about carbon-pricing instruments, including what I considered to be the symmetric instruments of a carbon tax and a carbon trading program. But the Hamilton Project leaders said no, they would find someone else to write about carbon taxes (which turned out to be Gib Metcalf), and they wanted me to “make the strongest case possible for” what is today called a cap-and-trade system. I did my best, and in the process I came to be identified – and to some degree may have become – an advocate for CO₂ cap-and-trade. For better or for worse, during the Obama administration transition, the design recommendations in my Hamilton Project paper became one of the starting points for efforts to structure the administration’s proposed CO₂ cap-and-trade system that became part of the failed Waxman-Markey legislation, H.R. 2454, the American Clean Energy and Security Act of 2009.

More than a decade later, I have written a new paper in which I seek to approach this question as I wished to in the first place, treating both instruments in a balanced manner, examining their merits and challenges, without necessarily favoring one or the other. On May 16, 2019, I presented this new paper at the National Bureau of Economic Research’s first annual Environmental and Energy Policy and the Economy Conference, held at the National Press Club in Washington, D.C. My topic was, “The Future of U.S. Carbon-Pricing Policy.” (It will be forthcoming in Environmental and Energy Policy and the Economy, volume 1, edited by Matthew Kotchen, James Stock, and Catherine Wolfram, published by the University of Chicago Press.) In today’s blog essay, I provide a very brief summary of the paper, based upon the presentation I made at the NBER conference. I hope you will find this of sufficient interest to download and read the complete paper.

Premises, Questions, and Conclusions

I began this research with two major premises: first, that economists and most other policy analysts agree that carbon-pricing will likely be a necessary (although not sufficient) part of any meaningful, long term U.S. climate change policy, because of: (1) feasibility – the necessity of affecting millions, indeed hundreds of millions, of decentralized decisions; (2) cost-effectiveness, given the tremendous heterogeneity of marginal abatement costs; and (3) the importance of providing incentives for carbon-friendly technological change. My second premise was that there is much less agreement among economists (and other policy analysts) regarding the choice of specific carbon-pricing policy instrument – carbon tax or cap-and-trade.

This prompts two questions: (1) how do the two major approaches to carbon pricing compare on relevant dimensions, including but not limited to efficiency, cost-effectiveness, and distributional equity? (2) Which approach is more likely to be adopted in the future in the United States?

Having carried out an exhaustive examination, two major conclusions stand out (among others). First, that the specific designs of carbon taxes and cap-and-trade are more consequential than the choice between the two instruments. And second, that political feasibility affects the normative merits of the two instruments, and vice versa.

Similarities & Symmetries

Of fourteen separate issues I examine, some appear at first to be key differences (in theory), but many of these differences fade on closer inspection, and depend on specifics of design.

First of all, carbon taxes and commensurate cap-and-trade turn out to be perfectly equivalent in regard to: (a) incentives for emission reduction (both can be upstream on the carbon content of fossil fuels); (b) aggregate abatement costs (both can be cost-effective, both provide the same incentives for technological change, and both can utilize offsets to further lower aggregate abatement costs); and (c) effects on competitiveness (both can lessen these impacts via appropriate border adjustment mechanisms).

Next, the two instruments are nearly equivalent in regard to possibilities for raising revenue (cap-and-trade can utilize auctions, but given the structure of Congressional committees, revenue recycling may be easier with taxes).

And these instruments are similar in regard to: (a) costs to regulated firms (cap-and-trade systems can freely allocate allowances, and taxes can provide inframarginal exemptions below a specified level of emissions); and (b) distributional impacts (the two instruments can be designed to be roughly equivalent in this regard).

Differences & Distinctions

Beginning with the least significant differences, there are relatively minor distinctions in terms of transaction costs (decreasing marginal transaction costs in cap-and-trade systems – such as with volume discounts on brokers’ fees – can violate the independence property, whereby the equilibrium allocation of allowances and hence aggregate costs are ordinarily independent of the initial allocation).

There are more meaningful, but still subtle differences with regard to: (a) performance in the presence of uncertainty (for this, I urge you to read at least this section of the complete paper, because new research suggests that the implications of the classic Weitzman rule in the presence of a stock externality are moderated – if not reversed – due to the persistent effects of technology shocks, which foster positive correlation between marginal benefits and marginal costs); and (b) linkage with other jurisdictions (it is easier with cap-and-trade systems, but tax systems can also be linked).

That said, there are significant differences between the instruments in terms of: (a) carbon-price volatility (a problem only with cap-and-trade systems, but a problem that can be mitigated with price collars and banking of allowances); (b) interactions with complementary policies (a significant issue with cap-and-trade systems, which is much less severe with carbon taxes, because the “waterbed effect” is eliminated); (c) market manipulation (there is a need for regulatory oversight in cap-and-trade systems, but tax evasion is a parallel issue in tax systems, although presumably less severe in the U.S. context); and (d) complexity and administrative requirements (cap-and-trade is certainly more complex and has greater administrative requirements, but one might ask whether a simple tax will remain “simple” as it works its way through the Congress).

Hybrid Policy Instruments and a Policy Continuum

Many of the remaining differences can diminish further with implementation. Indeed, hybrid policies which mix features of tax and cap-and-trade blur distinctions. For example, auctioning of allowances and the use of price collars bring cap-and-trade closer to a tax system; and quantity formula employed to adjust a tax, and the use of tax revenues to mitigate emissions bring a tax closer to cap-and-trade. The result is that the dichotomous choice between a carbon tax and cap-and-trade can become a choice of design elements along a policy continuum, and the design of these instruments can be more consequential than the choice between the two.

Which is More Likely to be Adopted – Taxes or Trading? Positive Political Theory

Framing this question in terms of the metaphor of a political market, it is helpful to think about political demand and political supply of policy instruments. In terms of the demand from interest groups, first, regulated industry may oppose an ordinary tax approach, as it typically leads to greater costs than the simplest cap-and-trade (or than a performance standard, for that matter), because private industry is paying not only for compliance costs, but also for the tax on residual emissions. Second, regulated industry may favor cap-and-trade, because it conveys scarcity rents to firms, and can provide entry barriers for potential new entrants, which can make the rents sustainable.

Environmental advocacy groups favor cap-and-trade, due to the emissions certainty it provides, but also because presumably they have a preference for policies that help obscure costs, and cap-and-trade does a better job of sweeping discussion of costs under the rug than does a tax. However, in the era since cap-and-trade was demonized as “cap-and-tax,” this difference may be much less than it was!

Turning to the supply side (within the legislature), the revenue from either a tax or auctioning of allowances can be attractive to government. And because of the independence property of cap-and-trade, legislators can allocate allowances to build political support without increasing the costs or reducing the effectiveness of the policy. Of course, this important political advantage becomes an economic disadvantage if it invites particularly harmful rent-seeking behavior. Finally, environmental policy makers tend to think in terms of pollution quantities, not prices.

Experience with Carbon Pricing: Emissions Coverage & Price in Implemented Initiatives

There are some fifty carbon-pricing systems in operation worldwide, with equal numbers of carbon taxes and carbon cap-and-trade systems. A quick comparison of these policies reveals two striking realities. First, the highest carbon prices (the height of the bars in the figure below) are for carbon taxes (in norther Europe). Second, the scope of coverage (the width of each bar in the figure) of cap-and-trade systems greatly exceeds that of carbon taxes. Putting the two features (severity and scope) together, a reasonable measure of the relative importance of the policies is given by multiplying the carbon price (tax level or market price of allowances) by the tons of coverage, that is, the respective areas in the figure. On this basis, it appears that political revealed preference has been weighted toward cap-and-trade (at least up until now).

Carbon Price & Emissions Coverage of Implemented Carbon-Pricing Initiatives

Which Has Worked Better – Experiences with Trading and Taxes

Based upon more than thirty years of experience with cap-and-trade systems, including but not limited to CO₂ programs, lessons regarding the design and efficacy of these systems can be drawn. In brief, there is empirical evidence for the following: cap-and-trade has proven to be environmentally effective and economically cost-effective; downstream, sectoral programs have been common, but economy-wide upstream systems are feasible; transaction costs have been low to trivial; a robust market requires a cap below business-as-usual; banking has been exceptionally important, representing a large share of the gains from trade; price collars are very beneficial; free allocation of allowances fosters political support, with a likely transition to greater auctioning over time; competitiveness impacts can be mitigated with an output-based updating allocation; “complementary policies” are common, but in some cases can have perverse consequences, including no additional emissions reduction, an increase in aggregate costs, and suppressed allowance prices.

Turning to experiences with carbon taxes, two applications stand out. First, there are the northern European carbon tax systems, initiated in the 1990s in Norway, Sweden, Denmark, and Finland. Typically these were elements of broader energy and excise tax reform initiatives, and some are at the highest levels of any carbon-pricing regimes worldwide. However, fiscal cushioning has been common for industries expressing concerns. That said, these taxes have raised significant revenues to finance spending or to lower other tax rates, but unfortunately, there is little empirical evidence of their emissions impacts.

More striking is British Columbia’s carbon tax, initiated in 2008, which comes closest to that recommended by economists. Currently, it is an upstream tax of $27/ton of CO₂, but with important exemptions in place for key industries. Importantly, 100% of tax revenue was originally refunded through general tax rate cuts, but over time, there has been more focus on tax cuts for specific sectors and locations. Although there is some debate in the literature, it appears to have been effective in reducing emissions.

Empirical Evidence for Positive Assessment

Given that the normative differences between the two instruments are minimal, a key question becomes which instrument is more politically feasible, and which is more likely — in practice — to be well designed. Based on experiences with cap-and-trade and carbon taxes, the relative masses in the figure above suggest that political revealed preference has favored the former. Furthermore, after years of deliberation, China has chosen trading for its national program (although it appears to be a set of sectoral tradable performance standards, not a true, mass-based cap-and-trade system). In addition, the new “Transportation and Climate Initiative” in the northeast United States was first proposed in terms of fuel taxes but is gravitating toward cap-and-trade. Also, New Jersey is preparing to rejoin the Regional Greenhouse Gas Initiative, and Oregon is poised to enact an economy-wide CO₂ cap-and-trade system this year. On the other hand, Washington State has twice defeated a carbon tax.

But past may not be prologue. The demonization of the Waxman-Markey trading system as “cap-and-tax” may have reduced the political advantage of cap-and-trade (that it can hide the costs). And there is clearly increasing interest in a national carbon tax in the policy world, including several bills in Congress and the prominent Climate Leadership Council proposal. On the other hand, the “Green New Deal” is silent about carbon-pricing of any kind.

It is worthwhile focusing on the political economy of the British Columbia carbon tax. Its successful enactment has been attributed to “the confluence of political conditions ripe for carbon taxation”: untapped hydroelectric potential; a strongly environmentalist electorate (as in the case of California’s move to cap-and-trade with Assembly Bill 32); a right-center government with trust from the business community (as with the George H.W. Bush administration’s SO₂ allowance trading system in the Clean Air Act amendments of 1990); and a premier with institutional capacity to pursue personal policy preferences. There has been increasing public support over time, due to the perception of emissions reductions without severe economic impacts, but political pressures have caused the evolution of the system from using revenues exclusively to cut distortionary taxes to greater use of tax cuts to favor specific sectors and regions.

Clearly, political pressures can drive up social costs with either type of carbon-pricing instrument. On the one hand, politics may disfavor the auctioning of allowances in cap-and-trade systems, while, on the other hand, politics may disfavor cost-effective cuts of distortionary taxes in tax systems.

Does Either Carbon-Pricing Instrument Dominate in Normative or Positive Terms?

When carbon taxes and cap-and-trade are designed to be truly comparable, their characteristics and outcomes are similar, and in some cases fully equivalent (normatively), in terms of their: emission reductions, abatement costs, revenue raising, costs to regulated firms, distributional impacts, and competitiveness effects. But on some other dimensions, there can be real differences in performance. The tax approach is favored by administrative requirements, interactions with complementary policies, and effects on carbon-price volatility; whereas cap-and-trade is favored by linkage with policies in other jurisdictions, and possibly by anticipated performance in the presence of uncertainty. In the positive political economy domain, the evidence is also decidedly mixed. Hence, there is not a strong case for the blanket superiority of either instrument. Differences in design simply dominate differences between the instruments themselves.

Can Carbon-Pricing be Made More Politically Acceptable?

The track record of 50 carbon-pricing policies cited above should be contrasted with the 176 countries with renewable energy policies or energy efficiency standards, as well as another 110 national and sub-national jurisdictions with feed-in tariffs. Hence, carbon pricing has not in general been the favored approach to climate change policy. Why is this the case? Survey and other evidence indicates that public perceptions – some of which are inaccurate – are primary factors behind aversion to carbon taxes: “personal costs too great; policy is regressive; could damage economy; will not discourage carbon-intensive behavior; and government just want the revenues.” So, one way to improve public acceptance could be through better information, that is, education.

But another way forward could be through judicious policy design, which may well depart from first-best design, including: phasing in taxes/caps over time (which was effective in California and British Columbia); earmarking revenues from taxes/auctions to finance additional climate mitigation, in contrast with optimizing the system via cuts in distortionary taxes; and/or using revenues for fairness purposes, such as with lump-sum rebates or rebates targeted to low-income and other particularly burdened constituencies (a carbon tax with “carbon dividends” or a cap-and-trade system in the form of “cap-and-dividend”).

Has the Defeat of National CO₂ Cap-and-Trade Initiatives Provided Openings for Carbon Tax Proposals?

Political polarization has decimated the key source of Congressional support for environmental/energy action, the political middle. And the successful political battle against the Obama administration’s CO₂ cap-and-trade legislation featured the effective demonization of that instrument as “cap-and-tax.” Does the consequent reputational loss for cap-and-trade provide a meaningful opening for the other carbon-pricing instrument – a carbon tax?

It would seem that large budgetary deficits ought to increase the attraction of new sources of revenue, but existing carbon tax proposals have largely been revenue-neutral. That said, it is surely true that there has been increased attention to carbon taxes from the “policy community,” with support coming not just from Democrats, but also from prominent Republican academic economists and former Republican high government officials. But – finally – what about in the real political world of those currently holding elective office in the federal government?

It is presumably good news for carbon tax proposals that they are not “cap-and-trade.” Perhaps that helps with the political messaging. But if conservative opposition could tarnish cap-and-trade as “cap-and-tax,” surely it will not be difficult to label a tax as a tax! And in addition to such opposition from the political right, it is – as of now – questionable whether the new left will want a carbon tax to be part of its “Green New Deal.”

Hence, in the short term, national carbon pricing of either type will likely continue to face an uphill battle. Therefore, in addition to considering second-best carbon-pricing design (as I recommended above), economists can work productively to catch up with political realities by considering better designs of second-best non-pricing instruments, such as clean energy standards.

But, at some point the politics will change, and it is important to be ready, which is why – for the longer term – ongoing research on carbon-pricing is very much warranted, particularly if it can be carried out in the context of real-world politics, and focus on policies that are likely at some point to prove feasible.

Cap-and-Trade versus the Alternatives for U.S. Climate Policy

Let’s credit Senator Lisa Murkowski (R-Alaska) for raising questions in the National Journal about the viability of cap-and-trade versus other approaches for the United States to employ in addressing CO₂ and other greenhouse gas emissions linked with global climate change.

Senator Murkowski says that only one approach – cap-and-trade – has received significant attention in the Congress. Let’s put aside for the moment the fact that most of the 1,428 pages of H.R. 2454 – the American Clean Energy and Security Act of 2009 (otherwise known as the Waxman-Markey bill) – are not about cap-and-trade at all, but about a host of other regulatory approaches (several of which are highly problematic, as I’ve discussed in a previous post). We can also put aside the fact that both conventional regulatory approaches and carbon taxes have been discussed repeatedly in numerous House and Senate committees over the past decade, and received detailed attention from a succession of U.S. administrations.

So, let’s not quibble about the Senator’s claim that cap-and-trade is the only approach that has received serious attention. Instead, let’s address the key substantive questions which Senator Murkowski raises, because they are important questions: Is cap-and-trade the most effective way of addressing climate change? And are there other approaches capable of achieving the same results at lower cost? From my perspective, as a card-carrying environmental economist, these are indeed the key questions.

While political leaders in the European Union, Canada, Australia, New Zealand, Japan, and the United States (Congress) move toward cap-and-trade systems as their preferred approach for achieving meaningful reductions in emissions of CO₂ and other greenhouse gases, many people – including some of my fellow economists — have been critical of the cap-and-trade approach in the climate context and have endorsed the use of carbon taxes. The Senator is correct that we should reflect on the merits of that alternative approach.

But, first, what about conventional regulatory approaches, that is, performance standards and technology standards?

Conventional Regulatory Standards

In short, experience has shown that such standards cannot ensure achievement of emissions targets, create problematic unintended consequences, and are very costly for what they achieve.

Why can conventional standard not ensure achievement of reasonable emissions targets? First, standards typically focus on new emissions sources, and do not address emissions from existing sources. Think about greenhouse gas standards for new cars and new power plants, for example. Second, standards cannot possibly address all types of new sources, given the ubiquity of energy generation and use (and hence CO₂ emissions) in a modern economy. Third, emissions depend upon many factors that cannot be addressed by standards, such as: emissions from existing sources and unregulated new sources; how quickly the existing capital stock is replaced; the growth in the number of new emissions sources; and how intensively emissions-generating plants and equipment are utilized.

Next, what about those unintended consequences? First, by reducing operating costs, energy-efficiency standards – for example — can cause more intensive use of regulated equipment (for example, air conditioners are run more often), leading to offsetting increases in emissions — the “rebound effect.” Second, firms and households may delay replacing existing equipment if standards make new equipment more costly. This is the well-known problem with vintage-differentiated regulations or “New Source Review.” Third, standards may encourage counterproductive, unintended shifts among regulated activities (for example, from purchasing cars to purchasing SUVs under the CAFE program). All of these unintended consequences result from the problematic incentives that standards can create, compared with the efficient incentives created by a cap-and-trade system (or a carbon-tax, for that matter).

If you favor a regulatory approach, then you may welcome what’s coming from EPA as a result of the Supreme Court ruling of a few years ago combined with the Administration’s endangerment finding. For my part, I don’t welcome it; I worry about it, because the set of regulatory approaches that could be forthcoming will accomplish relatively little, do so at an unnecessarily high cost, and hence play into the hands of opponents of progressive climate policy. (More about that in some other, future post.)

Putting a Price on Carbon

To virtually all participants in the policy world, it has become increasingly clear that the only approach that can do the job and do it cost-effectively is one which involves at its core putting a price on carbon. That leaves cap-and-trade and carbon taxes. Let me take these in turn.

Cap-and-Trade

Let’s step back from the debate regarding the details of the Waxman-Markey House bill or the new Senate proposal by Senators Boxer and Kerry, and think about the essence of the cap-and-trade approach. (For some of those details, however, please see my previous posts, where I have commented on various aspects of Waxman-Markey and described a proposal I developed for The Hamilton Project of an up-stream, economy-wide CO₂ cap-and-trade system to cost-effectively achieve meaningful greenhouse gas emissions reductions.)

Here are the basics. First, aggregate emissions from regulated sources are capped, and the cap is enforced through a requirement for affected firms to hold emissions allowances. Importantly, allowance trading minimizes costs of meeting the cap. It does this because allowances migrate to the highest-valued uses, covering emissions that are the most costly to reduce. So, the emission reductions undertaken are those that are least costly to achieve. In essence, the uniform market price of allowances creates incentives for all covered sources to reduce all emissions, and do so cost-effectively.

A cap-and-trade system can be more environmentally-effective and more cost-effective than standards. First, in terms of environmental-effectiveness, a cap-and-trade system can ensure achievement of emissions targets. Cap-and-trade allows policymakers to set specific overall emissions targets. And a well-enforced system guarantees achievement of those targets, because emissions will not exceed available allowances. An economy-wide, upstream cap-and-trade system on the carbon content of fossil fuels can cover all fossil-fuel-related CO₂ emissions without needing to regulate each emissions source individually.

In terms of cost-effectiveness, a well-designed cap-and-trade system minimizes emission reduction costs. Unlike NO_x, SO₂, and other pollutants, GHG emission reductions have the same effect no matter how, where, or when they are achieved. This makes the climate change problem unique in the degree to which compliance flexibility can be used to lower costs without compromising environmental integrity. Hence, a cap-and-trade system can minimize costs while still meeting environmental objectives by offering three forms of flexibility: what flexibility; where flexibility; and when flexibility.

In regard to “what flexibility,” many types of actions offer low-cost emission reductions, and a cap-and-trade system allows emission reductions through whatever measures are least costly. By contrast, standards can target only certain identified emission reduction measures, leaving other cost-effective opportunities untapped. Furthermore, predictions of what measures are cost-effective may be wrong.

In regard to “where flexibility,” the costs of emission reductions vary widely across industries, across facilities, and even across users of the same equipment. A cap-and-trade system exploits this variation in costs by achieving reductions wherever they are least costly. By contrast, standards would only be cost-effective if they accounted for all of the variation in costs across sectors, technologies, and regulated entities — but it is completely infeasible for standards to do this. Emission reduction costs across sectors and technologies change over time, making the flexibility offered by a cap-and-trade system even more valuable. Also, lower-cost opportunities to reduce emissions may exist in other countries. Importantly, a cap-and-trade system creates a common currency (emissions allowances) that makes it possible to link with other systems.

A cap-and-trade system also minimizes costs through “when flexibility.” Costs can be reduced through flexibility in the timing of emission reductions by avoiding: premature retirement of capital stock or lock-in of existing technologies; and unnecessarily costly reductions in one year due to unusual circumstances when less-costly offsetting reductions can be achieved in other years. A cap-and-trade can incorporate “when flexibility”
without compromising cumulative emissions targets through: allowance banking and borrowing; and multi-year compliance periods.

Beyond such “static cost-effectiveness,” cap-and-trade creates incentives for technology innovation, and thereby lowers long-run costs. By rewarding any means of reducing emissions, a cap-and-trade system provides broad incentives for any innovations that lower the cost of achieving emissions targets. Although standards may encourage development of lower cost means of meeting the standards’ specific requirements, they do not encourage efforts to exceed those standards.

Several cap-and-trade systems have been successful at achieving environmental goals and cost savings: the phase-out of leaded gasoline in the 1980s; the phase-out of ozone depleting substances; and the Clean Air Act amendments of 1990 SO₂ allowance trading program to cut acid rain by 50%. Perceived shortcomings in other cap-and-trade systems reflect design choices, not problems with the policy instrument itself. This applies both to California’s RECLAIM program, and the pilot phase of the EU Emissions Trading Scheme (which is operating successfully in its real, Kyoto phase).

In summary, compared with conventional standards, a cap-and-trade system can be more environmentally-effective and more cost-effective. As with any policy instrument, however, careful design is important.

Taxing Carbon

As I mentioned, it is clear that the only approach that can do the job and do it cost-effectively is one that involves putting a price on carbon. So, what about the other carbon-pricing approach — a carbon tax?

I am by no means opposed to the notion of a carbon tax, having written about such approaches for more than twenty years. Indeed, both cap-and-trade and carbon taxes are good approaches to the problem; they have many similarities, some tradeoffs, and a few key differences. I am opposed, however, to the confused and misleading straw-man arguments that have sometimes been used against cap-and-trade by carbon-tax proponents.

While there are tradeoffs between these two principal market-based instruments targeting CO₂ emissions — a cap-and-trade system and a carbon tax – the best (and most likely) approach for the short to medium term in the United States is a cap-and-trade system. I say this based on three criteria: environmental effectiveness, cost effectiveness, and distributional equity. So, my position is not capitulation to politics. On the other hand, sound assessments of environmental effectiveness, cost effectiveness, and distributional equity should surely be made in the real-world political context.

The key merits of the cap-and-trade approach I have described above are, first, the program can provide cost-effectiveness, while achieving meaningful reductions in greenhouse gas emissions levels. Second, it offers an easy means of compensating for the inevitably unequal burdens imposed by a climate policy. Third, it provides a straightforward means to harmonize with other countries’ climate policies. Fourth, it avoids the current political aversion in the United States to taxes. Fifth, it is unlikely to be degraded – in terms of its environmental performance and cost effectiveness – by political forces. And sixth, this approach has a history of successful adoption and implementation in this country over the past two decades.

Having said this, there are some real differences between taxes and cap-and-trade that need to be recognized. First, environmental effectiveness: a tax does not guarantee achievement of an emissions target, but it does provides greater certainty regarding costs. This is a fundamental tradeoff. Taxes provide automatic temporal flexibility, which needs to be built into a cap-and-trade system through provision for banking, borrowing, and possibly a cost-containment mechanism. On the other hand, political economy forces strongly point to less severe targets if carbon taxes are used, rather than cap-and-trade – this is not a tradeoff, and this is why environmental NGOs are opposed to the carbon-tax approach.

In principle, both carbon taxes and cap-and-trade can achieve cost-effective reductions, and – depending upon design — the distributional consequences of the two approaches can be the same. But the key difference is that political pressures on a carbon tax system will most likely lead to exemptions of sectors and firms, which reduces environmental effectiveness and drives up costs, as some low-cost emission reduction opportunities are left off the table. But political pressures on a cap-and-trade system lead to different allocations of allowances, which affect distribution, but not environmental effectives, and not cost-effectiveness.

Proponents of carbon taxes worry about the propensity of political processes under a cap-and-trade system to compensate sectors through free allowance allocations, but a carbon tax is sensitive to the same political pressures, and may be expected to succumb in ways that are ultimately more harmful: reducing environmental achievement and driving up costs.

The Bottom Line

The Hamilton Project staff concluded in an overview paper (which I highly recommend) that a well-designed carbon tax and a well-designed cap-and-trade system would have similar economic effects. Hence, they said, the two primary questions to use in deciding between them should be: which is more politically feasible; and which is more likely to be well-designed?

The answer to the first question is obvious; and I have argued here that given real-world political forces, the answer to the second question also favors cap-and-trade. In other words, it is important to identify and design policy that will be “optimal in Washington,” not just from the perspective of Cambridge, New Haven, or Berkeley.

In “policy heaven,” the optimal instrument to address climate-change emissions may well be a carbon tax (largely because of its simplicity), but in the real world in which policy is developed and implemented, cap-and-trade is the best approach if one is serious about addressing the threat of climate change with meaningful, effective, and cost-effective policies.

The Wonderful Politics of Cap-and-Trade: A Closer Look at Waxman-Markey

The headline of this post is not meant to be ironic. Despite all the hand-wringing in the press and the blogosphere about a political “give-away” of allowances for the cap-and-trade system in the Waxman-Markey bill voted out of committee last week, the politics of cap-and-trade systems are truly quite wonderful, which is why these systems have been used, and used successfully.

The Waxman-Markey allocation of allowances has its problems, which I will get to, but before noting those problems it is exceptionally important to keep in mind what is probably the key attribute of cap-and-trade systems: the allocation of allowances – whether the allowances are auctioned or given out freely, and how they are freely allocated – has no impact on the equilibrium distribution of allowances (after trading), and therefore no impact on the allocation of emissions (or emissions abatement), the total magnitude of emissions, or the aggregate social costs. (Well, there are some relatively minor, but significant caveats – those “problems” I mentioned — about which more below.) By the way, this independence of a cap-and-trade system’s performance from the initial allowance allocation was established as far back as 1972 by David Montgomery in a path-breaking article in the Journal of Economic Theory (based upon his 1971 Harvard economics Ph.D. dissertation). It has been validated with empirical evidence repeatedly over the years.

Generally speaking, the choice between auctioning and freely allocating allowances does not influence firms’ production and emission reduction decisions. Firms face the same emissions cost regardless of the allocation method. When using an allowance, whether it was received for free or purchased, a firm loses the opportunity to sell that allowance, and thereby recognizes this “opportunity cost” in deciding whether to use the allowance. Consequently, the allocation choice will not influence a cap’s overall costs.

Manifest political pressures lead to different initial allocations of allowances, which affect distribution, but not environmental effectiveness, and not cost-effectiveness. This means that ordinary political pressures need not get in the way of developing and implementing a scientifically sound, economically rational, and politically pragmatic policy. Contrast this with what would happen when political pressures are brought to bear on a carbon tax proposal, for example. Here the result will most likely be exemptions of sectors and firms, which reduces environmental effectiveness and drives up costs (as some low-cost emission reduction opportunities are left off the table). Furthermore, the hypothetical carbon tax example is the norm, not the exception. Across the board, political pressures often reduce the effectiveness and increase the cost of well-intentioned public policies. Cap-and-trade provides natural protection from this. Distributional battles over the allowance allocation in a cap-and-trade system do not raise the overall cost of the program nor affect its environmental impacts.

In fact, the political process of states, districts, sectors, firms, and interest groups fighting for their share of the pie (free allowance allocations) serves as the mechanism whereby a political constituency in support of the system is developed, but without detrimental effects to the system’s environmental or economic performance. That’s the good news, and it should never be forgotten.

But, depending upon the specific allocation mechanisms employed, there are several ways that the choice to freely distribute allowances can affect a system’s cost. Here’s where the “caveats” and “problems” come in.

First, auction revenue may be used in ways that reduce the costs of the existing tax system or fund other socially beneficial policies. Free allocations to the private sector forego such opportunities. Below I will estimate the actual share of allowance value that accrues to the private sector.

Second, some proposals to freely allocate allowances to electric utilities may affect electricity prices, and thereby affect the extent to which reduced electricity demand contributes to limiting emissions cost-effectively. Waxman-Markey allocates allowances to local distribution companies, which are subject to cost-of-service regulation even in regions with restructured wholesale electricity markets. So, electricity prices would likely be affected by these allocations under existing state regulatory regimes. The Waxman-Markey legislation seeks to address this problem by specifying that the economic value of the allowances given to electricity and natural gas local distribution companies should be passed on to consumers through lump-sum rebates, not through a reduction in electricity rates, thereby compensating consumers for increases in electricity prices, but without reducing incentives for energy conservation.

Third, and of most concern in the context of the Waxman-Markey legislation, “output-based updating allocations” provide perverse incentives and drive up costs of achieving a cap. This merits some explanation. If allowances are freely allocated, the allocation should be on the basis of some historical measures, such as output or emissions in a (previous) base year, not on the basis of measures which firms can affect, such as output or emissions in the current year. Updating allocations, which involve periodically adjusting allocations over time to reflect changes in firms’ operations, contrast with this.

An output-based updating allocation ties the quantity of allowances that a firm receives to its output (production). Such an allocation is essentially a production subsidy. This distorts firms’ pricing and production decisions in ways that can introduce unintended consequences and may significantly increase the cost of meeting an emissions target. Updating therefore has the potential to create perverse, undesirable incentives.

In Waxman-Markey, updating allocations are used for specific sectors with high CO₂ emissions intensity and unusual sensitivity to international competition, in an effort to preserve international competitiveness and reduce emissions leakage. It’s an open question whether this approach is superior to an import allowance requirement, whereby imports of a small set of specific commodities must carry with them CO₂ allowances. The problem with import allowance requirements is that they can damage international trade relations. The only real solution to the competitiveness issue is to bring non-participating countries within an international climate regime in meaningful ways. (On this, please see the work of the Harvard Project on International Climate Agreements.)

Also, output-based allocations are used in Waxman-Markey for merchant coal generators, thereby discouraging reductions in coal-fired electricity generation, another significant and costly distortion.

Now, let’s go back to the hand-wringing in the press and blogosphere about the so-called massive political “give-away” of allowances. Perhaps unintentionally, there has been some misleading press coverage, suggesting that up to 75% or 80% of the allowances are given away to private industry as a windfall over the life of the program, 2012-2050 (in contrast with the 100% auction originally favored by President Obama).

Given the nature of the allowance allocation in the Waxman-Markey legislation, the best way to assess its implications is not as “free allocation” versus “auction,” but rather in terms of who is the ultimate beneficiary of each element of the allocation and auction, that is, how the value of the allowances is allocated. On closer inspection, it turns out that many of the elements of the apparently free allocation accrue to consumers and public purposes, not private industry.

First of all, let’s looks at the elements which will accrue to consumers and public purposes. Next to each allocation element is the respective share of allowances over the period 2012-2050 (measured as share of the cap, after the removal – sale — of allowances to private industry from a “strategic reserve,” which functions as a cost-containment measure.):

a. Electricity and natural gas local distribution companies (22.2%), minus share (6%) that benefits industry as consumers of electricity (note: there is a consequent 3% reduction in the allocation to energy-intensive trade-exposed industries, below, which is then dedicated to broad-based consumer rebates, below), 22.2 – 6 = 16.2%

b. Home heating oil/propane, 0.9%

c. Protection for low- and moderate-income households, 15.0%

d. Worker assistance and job training, 0.8%

e. States for renewable energy, efficiency, and building codes, 5.8%

f. Clean energy innovation centers, 1.0%

g. International deforestation, clean technology, and adaptation, 8.7%

h. Domestic adaptation, 5.0%

The following elements will accrue to private industry, again with average (2012-2050) shares of allowances:

i. Merchant coal generators, 3.0%

j. Energy-intensive, trade-exposed industries (minus reduction in allocation due to EITE benefits from LDC allocation above) 8.0% – 3% = 5%

k. Carbon-capture and storage incentives, 4.1%

l. Clean vehicle technology standards, 1.0%

m. Oil refiners, 1.0%

n. Net benefits to industry as consumers of lower-priced electricity from allocation to LDCs, 6.0%

The split over the entire period from 2012 to 2050 is 53.4% for consumers and public purposes, and 20.1% for private industry. This 20% is drastically different from the suggestions that 70%, 80%, or more of the allowances will be given freely to private industry in a “massive corporate give-away.”

All categories – (a) through (n), above – sum to 73.5% of the total quantity of allowances over the period 2012-2050. The remaining allowances — 26.5% over 2012 to 2050 — are scheduled in Waxman-Markey to be used almost entirely for consumer rebates, with the share of available allowances for this purpose rising from approximately 10% in 2025 to more than 50% by 2050. Thus, the totals become 79.9% for consumers and public purposes versus 20.1% for private industry, or approximately 80% versus 20% — the opposite of the “80% free allowance corporate give-away” featured in many press and blogosphere accounts. Moreover, because some of the allocations to private industry are – for better or for worse – conditional on recipients undertaking specific costly investments, such as investments in carbon capture and storage, part of the 20% free allocation to private industry should not be viewed as a windfall.

Speaking of the conditional allocations, I should also note that some observers (who are skeptical about government programs) may reasonably question some of the dedicated public purposes of the allowance distribution, but such questioning is equivalent to questioning dedicated uses of auction revenues. The fundamental reality remains: the appropriate characterization of the Waxman-Markey allocation is that 80% of the value of allowances go to consumers and public purposes, and 20% to private industry.

Finally, it should be noted that this 80-20 split is roughly consistent with empirical economic analyses of the share that would be required – on average — to fully compensate (but no more) private industry for equity losses due to the policy’s implementation. In a series of analyses that considered the share of allowances that would be required in perpetuity for full compensation, Bovenberg and Goulder (2003) found that 13 percent would be sufficient for compensation of the fossil fuel extraction sectors, and Smith, Ross, and Montgomery (2002) found that 21 percent would be needed to compensate primary energy producers and electricity generators.

In my work for the Hamilton Project in 2007, I recommended beginning with a 50-50 auction-free-allocation split, moving to 100% auction over 25 years, because that time-path of numerical division between the share of allowances that is freely allocated to regulated firms and the share that is auctioned is equivalent (in terms of present discounted value) to perpetual allocations of 15 percent, 19 percent, and 22 percent, at real interest rates of 3, 4, and 5 percent, respectively. My recommended allocation was designed to be consistent with the principal of targeting free allocations to burdened sectors in proportion to their relative burdens, while being politically pragmatic with more generous allocations in the early years of the program.

So, the Waxman-Markey 80/20 allowance split turns out to be consistent — on average, i.e. economy-wide — with independent economic analysis of the share that would be required to fully compensate (but no more) the private sector for equity losses due to the imposition of the cap, and consistent with my Hamilton Project recommendation of a 50/50 split phased out to 100% auction over 25 years.

Going forward, many observers and participants in the policy process may continue to question the wisdom of some elements of the Waxman-Markey allowance allocation. There’s nothing wrong with that.

But let’s be clear that, first, for the most part, the allocation of allowances affects neither the environmental performance of the cap-and-trade system nor its aggregate social cost.

Second, questioning should continue about the output-based allocation elements, because of the perverse incentives they put in place.

Third, we should be honest that the legislation, for all its flaws, is by no means the “massive corporate give-away” that it has been labeled. On the contrary, 80% of the value of allowances accrue to consumers and public purposes, and some 20% accrue to covered, private industry. This split is roughly consistent with the recommendations of independent economic research.

Fourth and finally, it should not be forgotten that the much-lamented deal-making that took place in the House committee last week for shares of the allowances for various purposes was a good example of the useful, important, and fundamentally benign mechanism through which a cap-and-trade system provides the means for a political constituency of support and action to be assembled (without reducing the policy’s effectiveness or driving up its cost).

Although there has surely been some insightful press coverage and intelligent public debate (including in the blogosphere) about the pros and cons of cap-and-trade, the Waxman-Markey legislation, and many of its design elements, it is remarkable (and unfortunate) how misleading so much of the coverage has been of the issues and the numbers surrounding the proposed allowance allocation.