Optimal Migration: A World Perspective

We ask what level of migration would maximize world welfare. We find that skill-neutral policies are never optimal. An egalitarian welfare function induces a policy that entails moving mainly unskilled immigrants into the rich countries, whereas a welfare function skewed highly towards the rich countries induces an optimal policy that entails a brain-drain from the poor countries. For intermediate welfare functions that moderately favor the rich however, it is optimal to have no migration at all.