Beyond Income Differentials: Improving Our Understanding of Interstate Migration in Mexico

Estela Rivero-Fuentes, Princeton University

This paper uses innovative data and tecniques to better our understanding of the causes behind the directionality of interstate migration in Mexico. Past research has consistently shown that interstate migration is highly associated to wage and employment conditions in sending and receiving states, and to the distance separating the two areas. However, it has also been shown that these factors alone are not enough to explain what causes migration from certain states to be directed to some particular states and not others. Past case studies have shown that migration is more likely to occur between those states that have some cultural or economic connection that among those that do not (see for example Balán, 1981). Additionally, prior statistical analyses have hinted at the importance of these connections by showing that the effect of distance on the rate of state to state migration varies across states, and that geographical closeness to an important city disproportionally increases the rate of emigration (Greenwood and Ladman, 1978; and Fukurai, Pick and Butler, 1997). Nevertheless, no study that I know of has empirically tested the importance of historical, commercial, or cultural links between states yet. Part of the failure to consider these factors derives from the difficulty to operationalize them. This paper contributes in this sense by exploring the question of how historical, commercial and social links between states contribute to the explanation of the rate of state to state migration in Mexico between 1995 and 2000. To do so, I define the presence or absence of historical links between states according to the configuration of economic regions in different historic periods of Mexico. I also quantify the degree of a commercial connection between any two states through an analysis of cargo transportation flows during the last decade. Finally, by simultaneously analyzing the migratory flows to and from all states in the country, rather than concentrating on the migration to only one destination, the analysis in this paper allows to measure the relative importance of different factors in determining why emigration from a given state distributes as it does across all other states in the country.