Fungoes pulled up some interesting research on overextended sports markets, and linked it back to an old post I did on parity and how the existence of the AL and NL Central Divisions in baseball helps create parity in baseball. To further the point about the AL and NL Central Divisions acting as normalisers, the most recent World Series was a Central vs Central one. Which means, of the 10 teams in the 5 World Series since 2001, 4 have come from one of the East divisions, 3 from the West divisions, and 3 from the Central divisions. Hardly a sign of economic imbalance.
(Although there still should be a 3rd New York/New Jersey area team…)