Edward Castronova, a telecommunications professor at Indiana University, is studying how virtual ecomomies might shed light on our embattled ones offline.
I covered the underworld of online economies in a feature story for Spectrum magazine, which you can read here.
Here's one interesting nugget from Castronova's work, according to Reuters:
"After studying 314 million transactions within the fantasy world of Norrath in 'EverQuest II,' including trading in-game goods like armor, shields, leather, herbs and food, the researchers were able to calculate the GDP of one of the game servers (the back-end computer that hosts thousands of players in one world). As more people opened accounts and flocked to Norrath, spending money on new items, researchers saw inflation spike more than 50 percent in five months."