How Do Gasoline Prices Affect Fleet Fuel Economy?

Exploiting a rich dataset of passenger vehicle registrations in 20 US MSAs from 1997 to 2005, we examine the effects of gasoline prices on the automotive fleet's composition. We find that high gasoline prices affect fleet fuel economy through two channels: shifting new auto purchases towards more fuel-efficient vehicles, and speeding the scrappage of older, less fuel-efficient used vehicles. Policy simulations suggest that a 10 percent increase in gasoline prices from 2005 levels will generate a 0.22 percent increase in fleet fuel economy in the short run and a 2.04 percent increase in the long run.