The rhetoric of closed borders: quotas, lax enforcement and illegal migration

In 2008, approximately 12 million immigrants lived illegally in the United States, and large numbers of undocumented foreigners resided also in other advanced destination countries. Hence, attempts at controlling immigration flows seem to often fail. If governments are not enforcing their "official" immigration policy, why do they set such a policy in the first place? The purpose of this paper is to address this apparent puzzle, using a political agency framework. We consider a setting in which there is uncertainty on the supply of migrants, and the policy maker who faces elections can be of one of two types. Either he has preferences congruent with the median voter, or he desires a larger number of migrants, because he is interested in the maximization of social welfare or has fallen prey to a pro-immigration lobby. We show that, if the incumbent wants to admit more migrants than the median voter, he might find it optimal to announce a binding quota to be re-elected, and strategically relax its enforcement. The control of migration flows can take place at the border or domestically, and we argue that even if the former is less effective as a policy tool, it might be chosen in equilibrium. Thus, our model illustrates how strategic considerations by elected officials play an important role in explaining both the observed large number of illegal immigrants and lax enforcement.