THE SOCIAL-PROCESS OF UNDOCUMENTED BORDER CROSSING AMONG MEXICAN MIGRANTS

In this article a theoretical model is developed that views undocument ed border crossing as a well-defined social process influenced by the quantity and quality of human and social capital that migrants bring w ith them to the border, and constrained by the intensity and nature of U.S. enforcement efforts. Detailed histories of border crossing from undocumented migrants originating in 34 Mexican communities are employ ed to estimate equations corresponding to this model. On first trips, migrants rely on social ties to locate a guide to hell! them across th e border. As people gain experience in border crossing, they rely less on the assistance of others and more on abilities honed on earlier tr ips, thus substituting migration-specific human capital for general so cial capital. The probability of apprehension is influenced by differe nt factors on first and later trips. On initial trips, crossing with e ither a paid (coyote) or unpaid (a friend or relative) guide dramatica lly lowers the odds of arrest; but on subsequent trips mode of crossin g has no effect on the odds of apprehension, which are determined prim arily by the migrant's own general and migration-specific human capita l. On all trips, the intensity of the U.S. enforcement effort has litt le effect on the likelihood of arrest, but INS involvement in drug enf orcement sharply lowers the odds of apprehension.