There has been little rigorous evaluation of immigration barriers intended to improve domestic terms of employment by shrinking the workforce. We study one such barrier, a policy change that excluded almost half a million Mexican bracero seasonal agricultural workers from the United States....

An influential strand of research has tested for the effects of immigration on natives' wages and employment using exogenous refugee supply shocks as natural experiments. Several studies have reached conflicting conclusions about the effects of noted refugee waves such as the Mariel Boatlift in...