Strategic amnesty and credible immigration reform

Why do countries that impose employer sanctions to deter the illegal entry of foreign workers nevertheless grant amnesty to illegal immigrants? In this article, I provide a positive theory of amnesty provision in a model where the constrained optimal immigration reform, involving the joint use of employer sanctions and border interdictions, is time-inconsistent. In particular, my framework demonstrates that host countries of immigration can enhance the credibility of their immigration reforms by "binding their own hands" and strategically granting a socially excessive amount of amnesty to illegal workers.