Part of the rationale for the North American Free Trade Agreement was that it would increase trade and foreign direct investment (fdi) flows, creating jobs and reducing migration to the United States. Since poor data on illegal migration to the United States make direct measurement difficult, data on migration within Mexico, where census data permit careful analysis, are used instead to evaluate the mechanism behind predictions on migration to the United States. Specifications are provided for migration within Mexico, incorporating measures of cost of living, amenities, and networks. Contrary to much of the literature, labor market variables enter very significantly and as predicted once possible credit constraint effects are controlled for. Greater exposure to fdi and trade deters outmigration, with the effects working partly through the labor market. Finally, some tentative inferences are presented about the impact of increased fdi on Mexico–U.S. migration. On average, a doubling of fdi inflows leads to a 1.5–2 percent drop in migration.

This article employs established techniques from the spatial economics literature to identify regional patterns of income and growth in Mexico and to examine how they have changed over the period spanned by trade liberalization and how they may be linked to the income divergence observed following liberalization. The article first shows that divergence has emerged in the form of several income clusters that only partially correspond to traditional geographic regions. Next, when regions are defined by spatial correlation in incomes, a “south” clearly exists, but the “north” seems to be restricted to the states directly on the U.S. border and there is no “center” region. Overall, the principal dynamic of both the increased spatial dependency and the increased divergence lies not on the border but in the sustained underperformance of the southern states, starting before the North American Free-Trade Agreement, and to a lesser extent in the superior performance of an emerging convergence club in the north-center of the country.