During the period 1940–1985 the variance of average incomes across Mexican states fell by 60 percent. Beginning in 1985, however, and coinciding with the adoption of trade liberalization policies and other market-oriented reforms, state incomes began to diverge. Using microdata from the 1990 and 2000 Mexican Population Censuses, this study decomposes the recent divergence into components due to economy-wide changes in skill prices and components due to state-specific changes in the composition of workers. The study finds that the rise in the education premium hindered the progress of poor states and raised the variance of average state wages and labor earnings. However, educational attainment mostly compensated for this income-widening effe...