Kevin Roth

The Effects of Regulation in the Presence of Multiple Unpriced Externalities: Evidence from the Transportation Sector

In transportation systems with unpriced congestion, allowing single-occupant low-emission vehicles in high-occupancy vehicle (HOV) lanes to encourage their adoption exacerbates congestion costs for carpoolers. The resulting welfare effects of the policy are negative, with environmental benefits overwhelmingly dominated by the increased congestion costs. Exploiting the introduction of the Clean Air Vehicle Stickers policy in California with a regression discontinuity design, our results imply a best-case cost of

Vehicle Lifetime Trends and Scrappage Behavior in the U.S. Used Car Market

124 per ton of reductions in greenhouse gases,

Voluntary Exposure Benefits and the Costs of Climate Change

606,000 per ton of nitrogen oxides reduction, and

Weather, Traffic Accidents, and Exposure to Climate Change

505,000 per ton of hydrocarbon reduction, exceeding those of other options readily available to policymakers.

Weather, Traffic Accidents, and Climate Change

Using national data on vehicles in operation, we examine long-run changes in scrappage patterns in passenger cars and light trucks in the United States between 1969 and 2014. We find that the average lifetime for passenger cars has increased from 12.2 to 15.6 years between 1970s and the 2000s. Our central estimate of the elasticity of scrappage with respect to vehicle prices is -0.4, which is substantially different than values adopted in simulation models. These estimates imply that many policies aimed at reducing gasoline consumption, including Corporate Average Fuel Economy standards and gasoline taxes may produce changes in the used vehicle market that are different than prior studies suggest. We also note that consumer scrappage behavior seems to respond more strongly to changes in vehicle price than changes in gasoline price than standard theory would predict.

The Unintended Consequences of Regulation in the Presence of Multiple Unpriced Externalities: Evidence from the Transportation Sector

We identify behavioral responses, defined as “voluntary exposure benefits,” that have the potential to offset measured costs of climate change. We quantify these responses for the transportation sector. We find that warmer temperatures and reduced snowfall are associated with an increase in fatal accidents. While the application of these results to climate predictions suggests that weather patterns for the end of the century would lead to 381 additional fatalities per year, the associated welfare losses are almost completely offset by voluntary exposure benefits from increased traveling. Our results motivate carefully examining behavioral mechanisms to accurately estimate the welfare effects of climate change.

Is there an Energy Paradox in Fuel Economy

We identify behavioral responses, defined as “voluntary exposure benefits,�? that have the potential to offset measured costs of climate change. We quantify these responses for the transportation sector. We find warmer temperatures and reduced snowfall are associated with an increase in fatal accidents. While the application of these results to climate predictions suggests that weather patterns for the end of the century would lead to 381 additional fatalities per year, the associated welfare losses are almost completely offset by voluntary exposure benefits from increased traveling. Our results motivate carefully examining behavioral mechanisms to accurately estimate the welfare effects of climate change.