Many economists spend their days analyzing reams of data on things like housing starts or interest rates. But a recent job listing seeks an economist who can apply these number-crunching skills to another realm: the virtual economies of video games.

Valve Corp., a Bellevue, Wash., gaming company, is looking for an economist who can "provide insight into short- and long-term behavioral patterns of participants in virtual economies," according to the listing. "These economies are replete with rich trading patterns, fascinating...