It's a private laugh between the economist and the politician: Each is a skinny kid with a funny name. But Austan Goolsbee is no joke. As Barack Obama's top economic adviser, the 38-year-old University of Chicago economist is getting a lot of attention.

The two met when Obama was running for the U.S. Senate in 2004. Though Goolsbee is often dubbed a centrist, he's better understood as a proponent of behavioral microeconomics, which incorporates psychological findings into analyses of economic decisionmaking. Goolsbee has written about why watching TV isn't bad for kids and why the rich don't give more to charity. Steve Levitt, of Freakonomics fame, is both a University of Chicago colleague and an intellectual partner. The behavioral-microeconomics approach influences the policies that Obama has expounded. Consider his position on retirement savings, one of the few areas in which he and Hillary Clinton differ: Clinton has proposed new 401(k)-style savings vehicles. But seeing that most people don't sign up for the plans available to them, Obama wants to make 401(k) enrollment automatic unless one opts out. A champion debater at Yale and a member of an improvisational troupe, Goolsbee is quick on his feet and a regular on TV. If Obama makes it to the White House, expect to see much more of him.