Smog is sharply declining in growing cities. This suggests that emissions per mile of driving is declining faster than overall vehicle mileage is growing. This paper analyzes emissions for over 24,000 vehicles tested at random between 1997 and 1999 in California's Random Roadside Emissions...

Airline fuel consumption is costly for the firms and for society as well due to a climate-change externality. We study how fuel price changes affect cost-minimizing choices by airlines that have implications for the extent of this externality. The airline industry's capital stock can be easily...

This paper estimates fossil fuel subsidies and the economic and environmental benefits from reforming them, focusing mostly on a broad notion of subsidies arising when consumer prices are below supply costs plus environmental costs and general consumption taxes. Subsidies are $4.9 trillion...

The favored federal policy to address climate change is a domestic cap-and-trade system. However, a vocal minority of political leaders have begun arguing in favor of a carbon tax. Carbon taxes seem particularly attractive both for fiscal reasons and because they provide certainty over the price...