Abstract: 

This paper investigates the effectiveness of immigration control policies when the duration

of stay of illegal immigrants is endogenous because they may return home voluntarily. It shows

that return intentions matter, because then policies will typically affect not only the number

of immigrants, but also their duration of stay. For example, we  find that spending on border

enforcement can potentially increase the total amount of illegal labor in the receiving country.

Second, in-site inspections reduce illegal labor, unless there is an amnesty: then, they can have

the opposite effect. Third, fines on apprehended migrants have only limited effect.