Jonathan E. Hughes

Some Inconvenient Truths About Climate Change Policy: The Distributional Impacts of Transportation Policies

Climate policy has favored costly measures that implicitly or explicitly subsidize lowcarbon fuels.We simulate four transportation sector policies: cap and trade (CAT), ethanol subsidies, a renewable fuel standard (RFS), and a lowcarbon fuel standard. Our simulations confirm that alternatives to CAT are 2.5 to 4 times more costly but are amenable to adoption due to right-skewed distributions of gains. We analyze voting on the Waxman-Markey (WM) CAT bill. Conditional on a district’s CAT gains, a district’s RFS gains are negatively correlated with the likelihood of voting for WM. Our analysis supports campaign contributions as a partial mechanism.

Getting Green with Solar Subsidies: Evidence from the California Solar Initiative

Subsidies to promote energy efficiency and renewable energy have been widely adopted. We study the California Solar Initiative and find upfront rebates have a large effect on residential solar installations. We exploit variation in rebate rates across electric utilities over time and control for time-varying factors that affect solar adoption. Our preferred estimates suggest increasing rebates from

Carpooling and Driver Responses to Fuel Price Changes: Evidence from Traffic Flows in Los Angeles

5,600 to

WHEN SHOULD DRIVERS BE ENCOURAGED TO CARPOOL IN HOV LANES

6,070 would increase installations by 10%. Overall, we predict 53% fewer installations would have occurred without subsidies. Over 20 years, these additional installations reduce carbon dioxide emissions between 2.3 and 3.4 million metric tons and local air pollutants (NOx) by 1,100 to 1,700 metric tons. Of the

Food vs. Fuel? Impacts of Petroleum Shipments on Agricultural Prices.

440 million in rebates awarded,

Evidence of a Shift in the Short-Run Price Elasticity of Gasoline Demand

121 million were rents to installations that would have occurred absent rebates. We estimate program costs of

Greenhouse Gas Reductions Under Low Carbon Fuel Standards

0.06 per kilowatt hour and between

Strategic Policy Choice in State-Level Regulation: The Epa's Clean Power Plan

130 and

The higher price of cleaner fuels: Market power in the rail transport of fuel ethanol

196 per metric ton of carbon dioxide.

Unintended Consequences of Transportation Carbon Policies: Land-Use, Emissions, and Innovation

Understanding how drivers respond to fuel price changes has important implications for highway congestion, accidents, carbon policy, local air pollution and taxation. We examine the underexplored relationship between fuel prices and carpooling. Using a simple theoretical model we show that traffic flows in mainline lanes decrease when fuel prices increase. However in carpool (HOV) lanes, flow can either increase or decrease. Traffic flows in mainline lanes are shown to be more responsive to price changes when the presence of a carpool lane provides a substitute to driving alone. We test these predictions using eight years of traffic data for 1,700 locations in Los Angeles. The mean elasticity of flow with respect to fuel price is 0.136 for HOV lanes. This implies 10 additional carpools per hour for a 10 percent increase in fuel price. For mainline lanes, flow elasticities are -0.083 and -0.050 for highways with and without an HOV lane. These estimates imply that the mean highway with an HOV lane experiences a 30 percent larger decrease in hourly flow compared to the mean highway without an HOV lane. Flows in HOV lanes show an immediate decrease following a price increase but respond positively to price increases over time, which suggests time is an important input to carpool formation.