Fuel economy standards change the composition of the vehicle fleet, potentially influencing accident fatality risks. I estimate the direction and magnitude of this impact, introducing a correction for selection on driver behavior. A policy application using my new estimates shows that the present distinction between light trucks and cars in fuel economy rules has very negative consequences for overall safety: Each MPG increment to the standard results in an additional 150 fatalities per year in expectation. My correction for selection is pivotal in this finding. I then demonstrate a simple alternative regulation that can produce near-zero changes in accident fatalities.

We estimate the sensitivity of scrap decisions to changes in used car values and show how this “scrap elasticity” produces emissions leakage under fuel efficiency standards, a process known as the Gruenspecht effect. We first estimate the effect of gasoline prices on used vehicle values and scrappage of vehicles with different fuel economies. We then estimate the scrap elasticity itself, which we find to be −0.7. When applied in a model of fuel economy standards, 13–16 percent of the expected fuel savings leak away through the used vehicle market. This effect rivals or exceeds the importance of the often-cited mileage rebound effect. (JEL H23, L62, L78, Q35, Q38, Q48, Q58)

We examine the impacts of increased US gasoline taxes in a model that links the markets for new, used, and scrapped vehicles and recognizes the considerable heterogeneity among households and cars. Household choice parameters derive from an estimation procedure that integrates individual choices for car ownership and miles traveled. We find that each cent-per-gallon increase in the price of gasoline reduces the equilibrium gasoline consumption by about 0.2 percent. Taking account of revenue recycling, the impact of a 25-cent gasoline tax increase on the average household is about $30 per year (2001 dollars). Distributional impacts depend importantly on how additional revenues from the tax increase are recycled. (JEL D12, H22, H25, L62, L71)

The world has 1.4 billion passenger vehicles. How should governments regulate their air pollution emissions? A Pigouvian tax is technologically infeasible. Most countries instead rely on exhaust standards that limit air pollution emissions per mile for new vehicles. We assess the effectiveness and efficiency of these standards, which are the centerpiece of U.S. Clean Air Act regulation of transportation, and counterfactual policies. We show that the air pollution emissions per mile of new U.S. vehicles has fallen spectacularly, by over 99%, since standards began in 1967. Several research designs with a half century of data suggest that exhaust standards have caused most of this decline. Yet exhaust standards are not cost-effective in part because they fail to encourage scrap of older vehicles, which account for the majority of emissions. To study counterfactual policies, we develop an analytical and a quantitative model of the vehicle fleet. Analysis of these models suggests that tighter exhaust standards increase social welfare and increasing registration fees on dirty vehicles yields even larger gains by accelerating scrap, although both reforms have complex effects on inequality.

Corrective taxes can solve many market failures, but actual policies frequently deviate from the theoretical ideal because of administrative or political constraints. We present a method to quantify the efficiency costs of constraints on externality-correcting policies or, more generally, the costs of imperfect pricing, using simple regression statistics. Under certain conditions, the R2 and the sum of squared residuals from a regression of true externalities on policy variables measure relative welfare gains from policies. We illustrate via four empirical applications: random mismeasurement of externalities, imperfect electricity pricing, heterogeneity in the longevity of energy-consuming durable goods, and imperfect spatial policy differentiation.

Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-market Study by Antonio M. Bento, Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen and Roger H. von Haefen. Published in volume 95, issue 2, pages 282-287 of American Economic Review, May 2005