Immigration has once again become an important and contentious issue in the European Union. This paper, therefore, contributes to the debate by analysing different dimensions of the problem in the context of EU enlargement, using a consistent model of migration. This recognises that, within Europe, most migration is not permanent, but part of a process of mobility in which both return and serial migration are natural economic responses to a dynamic economy. We show that there are beneficial effects of migration, on both the home (origin) and host (destination) regions. We also bring forward some evidence to suggest that there is little difference in the preferences of migrants and non- migrants and, more importantly, between those moving legally and illegally. This leads us to some observations on the development of a more efficient policy towards migration both within and into the EU.