The social process of undocumented border crossing among Mexican migrants

In this article a theoretical model is developed that views undocumented border crossing as a well-defined social process influenced by the quantity and quality of human and social capital that migrants bring with them to the border, and constrained by the intensity and nature of US enforcement efforts. Detailed histories of border crossing from undocumented migrants originating in 34 Mexican communities are employed to estimate equations corresponding to this model. On first trips, migrants rely on social ties to locate a guide to help them across the border. As people gain experience in border crossing, they rely less on the assistance of others and more on abilities honed on earlier trips, thus substituting migration-specific human capital for general social capital. The probability of apprehension is influenced by different factors on first and later trips. On initial trips, crossing with either a paid (coyote) or unpaid (a friend or relative) guide dramatically lowers the odds of arrest; but on subsequent trips mode of crossing has no effect on the odds of apprehension, which are determined primarily by the migrant's own general and migration-specific human capital. On all trips, the intensity of the US enforcement effort has little effect on the likelihood of arrest, but INS involvement in drug enforcement sharply lowers the odds of apprehension.