This article examines the impact of hometown market size on competitive balance in Major League Baseball. We use a four-equation simultaneous model of win percent, team payroll, team total revenue, and team local revenue in order to avoid simultaneity bias in the estimates. Using two-stage least squares, our results show that consolidated metropolitan statistical area population does have a statistically significant positive impact on local revenue. This leads to increased payroll, which has a significantly positive, but small, impact on win percent. Specifically, the estimated impact of an additional one million in population ranges from 0.233 to 1.126 additional wins per season. (JEL L38)