Gravity and Localized Migration

I construct a simple gravity model of migration that explains the majority of variation in Mexico-US bilateral migrant stock sizes at the relatively localized state-state level. Relying on a novel dataset that permits the linking of Mexican migrants' US states of residence with Mexican states of origin, I show that the gravity model provides an important framework for examining the determinants of migration at the localized level, specifically addressing the choice of states of residence within the destination country by migrants spread across varied states of the origin country. This explicit inclusion of state (rather than national) characteristics allows for greater accuracy in measuring the potential determinants of migration within the gravity model, including the distance and mass variables fundamental to the gravitational relationship.