In recent empirical literature on spatial agglomeration, many papers find evidence consistent with location-specific externalities of some sort. Our willingness to accept evidence of agglomeration economies depends on how well key estimation problems have been addressed. Three issues are...

Does regional economic integration affect the location of economic activity inside countries? In this paper, I discuss recent academic literature on whether the movement towards free trade in North America has influenced the spatial organization of production in Canada, Mexico, or the United...

In this paper, I examine the relationship between increasing returns to scale and the geographic concentration of economic activity. Using data on U.S. counties, I estimate the structural parameters of the Krugman (1991) model of economic geography. The specification I use, which is derived from...

In this paper, I examine whether U.S.-Mexico economic integration is causing economic activity in the United States to relocate to the U.S.-Mexico border region. The approach I take is to study U.S.- Mexico border-city pairs. Border cities are natural laboratories in which to study the effects...

In this paper, I examine how the growth of offshore assembly in Mexico has affected manufacturing activity in U.S. border cities. Under the offshore assembly provision of the U.S. tariff schedule, goods that are assembled abroad using U.S.-manufactured components receive preferential tariff...

This paper develops a model of regional production networks based on localization economies. I consider an industry with two activities: one with location-specific external economies, the other with constant returns. Under autarky, localization economies imply the formation of an industry...

In this paper, I study the effect of economic integration with the United States on state-industry employment growth in Mexico. I disentangle the effects of two opposing forces on regional labor demand: transport-cost considerations, which, all else equal, encourage firms to relocate their...

In this paper, I selectively discuss recent empirical work on the consequences of global labor mobility. I examine how international migration affects the incomes of individuals in sending and receiving countries and of migrants themselves. Were a social planner to choose the migration policies...

In this paper, I selectively review recent literature on illegal migration from Mexico to the United States. I begin by discussing methods for estimating stocks and flows of illegal migrants. While there is uncertainty about the size of the unauthorized population, new data sources make it...

In this paper, I examine changes in labor supply and earnings across regions of Mexico during the 1990s. I focus the analysis on individuals born in states with either high-exposure or low-exposure to emigration, as measured by historical data on state migration to the United States. During the...