What is a feasible and efficient policy to regulate air pollution from vehicles? 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...

"Policy-makers have instituted a variety of fuel economy tax policies -- polices that tax or subsidize new vehicle purchases on the basis of fuel economy performance -- in the hopes of improving fleet fuel economy and reducing gasoline consumption. This article reviews existing policies and...

"Notches --- where small changes in behavior lead to large changes in a tax or subsidy --- figure prominently in many policies, but have been rarely examined by economists. In this paper, we analyze a class of notches associated with policies aimed at improving vehicle fuel economy. We provide...

"This paper investigates the response of young people in the United States to state laws dictating the minimum age at which individuals could marry, with and without parental consent. We use variation across states and over time to document behavioral responses to laws governing the age of...