Greg Mankiw links to this paper (warning: pdf) by Washington University economics grad student Charles Courtemanche (he says on his Website that he’s on the job market), who contends:
that an additional $1 in real gasoline prices would reduce obesity in the U.S. by 15% after five years, and that 13% of the rise in obesity between 1979 and 2004 can be attributed to falling real gas prices during this period. I also provide evidence that the effect occurs both by increasing exercise and by lowering the frequency with which people eat at restaurants.
My initial inclination was to think this is just an economist being too fancy with his equations and harboring too much faith in the power of monetary incentives to shape behavior. But then I thought about it: Here in Manhattan, where we don’t have a whole lotta fat people, it costs $400 a month to park your car in garage or several hours a week of active and sometime aggressive work to park on the street without getting a ticket. Which is sort of like a very high gas tax.
Courtemanche, who appears to be pretty skinny, has been doing some other fascinating work on obesity. A couple other papers (also pdfs): Working Yourself to Death? The Relationship Between Work Hours and Obesity and Rising Cigarette Prices and Rising Obesity: Coincidence or Unintended Consequence?
Come on, universities of America. This man is brilliant. Give him a job!