The volume addresses challenging and under-researched themes on the subject of migration. It debates the question of whether we ought to recognize a human right to immigrate, and whether it might be legitimate to restrict emigration. The authors critically examine criteria for selecting would-be migrants, and for acquiring citizenship. They discuss tensions between the claims of immigrants and existing residents, and tackle questions of migrant worker exploitation and responsibility for refugees. The book illustrates the importance of drawing on the tools of political theory to clarify, criticize, and challenge the current terms of the migration debate.