Gilbert E. Metcalf

Energy conservation investment Do consumers discount the future correctly

We argue that the apparently high discount rates attributed to investors making energy conservation investments are not irrational or the result of some market failure. Rather they may result from an investor recognizing that many conservation investments entail substantial sunk costs. In the presence of these costs and uncertainty over future conservation savings, consumers should use a higher hurdle rate for investment than if there were no uncertainty. Simulations suggest that the hurdle rate should be about four times greater than the standard rate. An implication of our model is that tax subsidies for the purchase of conservation capital are likely to be ineffective. We discuss alternative policy approaches which are more likely to increase energy-efficient investment, namely mandatory efficiency standards and energy taxes.

Environmental Controls, Scarcity Rents, and Pre-Existing Distortions

Debate about the Double Dividend Hypothesis has focused on whether an environmental policy raises revenue that can be used to cut other distorting taxes. In this paper, we show that this focus is misplaced. We derive welfare results for alternative policies in a series of analytical general equilibrium models with clean and dirty goods that might be produced using emissions as well as other resources, in the presence of other pre-existing distortions such as labor taxes or even monopoly pricing. We show that the same welfare effects of environmental protection can be achieved, without exacerbating the labor distortion, by taxes that raise revenue, certain command and control regulations that raise no revenue, and even subsidies that cost revenue. Instead, the pre-existing labor tax distortion is exacerbated by policies that generate privately-retained scarcity rents. These rents raise the cost of production, raise equilibrium output prices, and thus reduce the real net wage. Such policies include both quantity-restricting command and control policies and certain marketable permit policies.

Energy tax credits and residential conservation investment: Evidence from panel data

Using panel data on individual tax returns and variation in state tax policy, we measure the impact of government tax policies to encourage residential conservation investment on the probability of making these investments. Unlike previous work, we account for unobserved heterogeneity in tastes for energy-saving activities and its possible correlation with tax policy at the state level. We find that controlling for unobserved heterogeneity is very important. Based on our preferred point estimate of the tax price coefficient, a 10 percentage point change in the tax price for energy investment would lead to a 24 percent increase in the probability of making an investment.

The Design of a Carbon Tax

We consider the design of a tax on greenhouse gas emissions for a developed country such as the United States. We consider three sets of issues: the optimal tax base, issues relating to the rate (including the use of the revenues and rate changes over time) and trade. We show that a well-designed carbon tax can capture about 80% of U.S. emissions by taxing fewer than 3,000 taxpayers and up to almost 90% with a modest additional cost. We recommend full or partial delegation of rate setting authority to an agency to ensure that rates reflect new information about the costs of carbon emmissions and of abatement. Adjustments should be made to the income tax to ensure that a carbon tax is revenue neutral and distributionally neutral. Finally, we propose an origin-based system for trades with countries that have an adequate carbon tax. We suggest a system that imposes presumptive border tax adjustments with the ability of an individual firm to prove that a different rate should apply. The presumptive tax could be based either on average emissions for production of the item by the exporting country or by the importing country.

Designing a Carbon Tax to Reduce U.S. Greenhouse Gas Emissions

This article describes a revenue and distributionally neutral approach to reducing U.S. greenhouse gas emissions that uses a carbon tax. The revenue from the carbon tax is used to finance an environmental earned income tax credit designed to be distributionally neutral. The credit is linked to earned income and helps offset the regressivity of the carbon tax. The carbon tax reform proposal is also revenue neutral and avoids conflating carbon policy with debates over the appropriate size of the federal budget. The article provides a distributional analysis of the proposal and also makes a number of political, economic, and administrative arguments in favor of a carbon tax and responds to the arguments that have commonly been made against using a tax-based approach to reducing U.S. emissions.

Investment under alternative return assumptions Comparing random walks and mean reversion

Many recent theoretical papers have come under attack for modeling prices as Geometric Brownian Motion. This process can diverge over time, implying that firms facing this price process can earn infinite profits. We explore the significance of this attack and contrast investment under Geometric Brownian Motion with investment assuming mean reversion. While analytically more complex, mean reversion in many cases is a more plausible assumption, allowing for supply responses to increasing prices. We show that cumulative investment is generally unaffected by the use of a mean reversion process rather than Geometric Brownian Motion and provide an explanation for this result.

Assessment of U.S. Cap-and-Trade Proposals

In 2007 the US Congress began considering a set of bills to implement a cap-and-trade system to limit the nations greenhouse gas (GHG) emissions. The MIT Integrated Global System Model (IGSM)—and its economic component, the Emissions Prediction and Policy Analysis (EPPA) model—were used to assess these proposals. In the absence of policy, the EPPA model projects a doubling of US greenhouse gas emissions by 2050. Global emissions, driven by growth in developing countries, are projected to increase even more. Unrestrained, these emissions would lead to an increase in global CO2 concentration from a current level of 380 ppmv to about 550 ppmv by 2050 and to near 900 ppmv by 2100, resulting in a year 2100 global temperature 3.5–4.5°C above the current level. The more ambitious of the Congressional proposals could limit this increase to around 2°C, but only if other nations, including developing countries, also strongly controlled greenhouse gas emissions. With these more aggressive reductions, the economic cost measured in terms of changes in total welfare in the United States could range from 1.5% to almost 2% by the 2040–2050 period, with 2015 CO2-equivalent prices between

Tax Distortions and Global Climate Policy

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The Effect of Federal Tax Deductibility on State and Local Taxes and Spending

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Economics and rational conservation policy

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