Research

Publications

From Cradle to Junkyard: Assessing the Life-cycle Greenhouse Gas Benefi ts of Electric Vehicles
Research in Transportation Economics, October 2015
With Alissa Kendall and David Rapson
U.S. programs subsidize electric vehicles (EVs) in part to reduce greenhouse gas (GHG) emissions. We model a suite of life cycle GHG emissions considerations to estimate the GHG abatement potential from switching from an internal combustion engine vehicle (ICE) to an EV in the continental U.S. The GHG intensity of EVs hinges on the electricity and ambient temperature when charged and operated. Both have high spatial and temporal heterogeneity, yet are typically modeled inadequately or overlooked entirely. We calculate marginal emissions, including renewables, for electricity by region and test forecasted grid composition to estimate future performance. Location and timing of charging are important GHG determinants, but temperature effects on EV performance can be equally important. On average, EVs slightly reduce GHGs relative to ICEs, but there are many regions where EVs provide a decisive benefit and others where EVs are significantly worse. The forecasted grid shifts from coal towards renewables, improving EV performance; the GHG benefit per EV in western states is roughly $425 today and $2400 in 2040.
Online Appendix

Working Papers

Job Market Paper: Dam Spillovers: Direct costs and spillovers from environmental constraints on hydroelectric generation
2017 United States Association of Energy Economics Best Student Paper Award
Full accounting of costs and benefits are essential to policy analysis, but many regulations may have effects beyond firms directly constrained by regulation. Using a set of regulations on allowed stream flows below hydroelectric dams, this paper estimates both the direct costs of regulations to dam owners and spillovers to other firms participating in the same output market. Combining a novel method of imputing hour-to-hour operations at hydroelectric dams and previously unidentified policy variation in a regression discontinuity design, I find large effects from regulation, increasing the total costs of electricity generation as much as 19.8% and leading to millions of dollars per year in additional pollution exernalities. Ignoring spillovers would substantially underestimate true policy costs, leading to suboptimal policy. Variation in these policies are analogous to an experiment manipulating the quantity of available electricity storage. My estimates show the social value electricity storage capacity is at most 72% of the capital cost of the best-available technology. Decomposition of the channels through which policy effects spill over reveal the cost of these policies will continue to grow as climate change exacerbates water scarcity and the deployment of renewable generation technologies increases.
Air Quality and Error Quantity: Pollution and Performance in a High-skilled, Quality-focused Occupation
With Anthony Heyes and Soodeh Saberian
Conditionally Accepted, Journal of the Association of Environmental and Resource Economists
We provide the first evidence that short-term exposure to air pollution affects the work performance of a group of highly-skilled, quality-focused employees. We observe the decision-making of a panel of professional baseball umpires, quasi-randomly assigned to varying air quality across time and space. Unique characteristics of this setting combined with high-frequency data disentangle the effects of multiple pollutants and identify previously under-explored acute effects. Our preferred estimates indicate that a 1 ppm increase in 3-hour CO causes an 11.5% increase in the propensity of umpires to make incorrect calls (an extra 2.0 incorrect calls per 100 decisions). Likewise a 10 μg/m3 increase in 12-hour PM2.5 causes a 2.6% increase in the propensity of umpires to make incorrect calls (an extra 0.4 incorrect calls per 100 decisions). We control carefully for a variety of potential confounders and the results prove robust to a battery of robustness and falsification checks. Effects are identified at pollution levels well below current EPA standards. When interacted with typical patterns of air quality conditions in major US cities the effects prove substantial, regularly exceeding a 3% productivity decrement across US metropolitan areas.
Online Appendix
Attribute Substitution in Household Vehicle Portfolios
With Kenneth Gillingham, Christopher R. Knittel, and David Rapson
NBER Working Paper No. 23856
Household preferences for goods with a bundle of attributes may have complex substitution patterns when one attribute is changed. For example, a household faced with an exogenous increase in the size of one television may choose to decrease the size of other televisions within the home. This paper quantifies the extent of attribute substitution in the context of multi-vehicle households. We deploy a novel identification strategy to examine how an exogenous change in the fuel economy of a kept vehicle ffects a household's choice of a second vehicle. We find strong evidence of attribute substitution in the household vehicle portfolio. This effect operates through car attributes that are correlated with fuel economy, including vehicle footprint and weight. Our findings suggest that attribute substitution exerts a strong force that may erode a substantial portion of the expected future gasoline savings from fuel economy standards, particularly those that are attribute-based. Elements of our identification strategy are relevant to a broad class of settings in which consumers make sequential purchases of durable portfolio goods.

Selected Works in Progress

Generating Commitment Issues: Estimating Unit Commitment Costs in Wholesale Electricity Markets

In the Media

Climate benefits from electric car equals $425, study says, San Diego Union Tribune, September 2015
California drivers suffer from 'Diet soda effect', paring Priuses with gas-guzzline SUVs, San Fransisco Chronicle, September 2017
Californians With Fuel-Efficient Cars Fall Prey to "Diet Soda" Effect Capital Public Radio, September 2017