Policy Climates, Enforcement Rates, and Migrant Behavior: Is Self‐Deportation a Viable Immigration Policy?

U.S. immigration policy has been the subject of considerable debate in recent years. Previous research has focused on how temporal variation in federal policy has altered the migratory behavior of immigrants. The effect of spatial variation in enforcement remains untested. Relying on the criminological distinction between general and specific deterrence, we argue that high rates of enforcement are unlikely to encourage undocumented immigrants to self-deport. We also examine the effects cultural and economic immigration policies adopted by the states. Previous research suggests that migrants will choose to remain in states with favorable environments, but this claim has not been directly tested. We draw on data from the Mexican Migration Project (MMP) to address these gaps. MMP data are supplemented with government data on federal enforcement obtained from Immigration and Customs Enforcement (ICE) and measures of state policy. Our findings suggest that higher rates of enforcement and the establishment of negative policy environments do not encourage undocumented immigrants to leave the United States at a higher rate than their documented counterparts do. Rather, high enforcement contexts exaggerate the differences between documented and undocumented migrant behavior, with undocumented migrants staying longer. Liberal state policies have no discernible effect.