There are continuing efforts at the monetary integration and unionization in West Africa. Several academics argue that a monetary union among West African states would be costly because of the magnitude of asymmetric shocks. A common monetary policy is inappropriate and ineffective to respond to...

We build a simple model of self-selection into migration and immigration policy determination. We first show that the effect of any immigration policy can be decomposed into a size and a composition effect. We then explore how the optimal policy may change once the latter effect is considered.