As never before, young people in the poorest countries are aware of opportunities elsewhere. Most of them want to migrate to the high-income countries. The response of the high-income societies has been schizophrenic: the European former colonial powers display a mixture of guilt andresentment; North America oscillates between seeing immigrants as a new wave of opportunity and a threat to living standards. Potentially, the scale of migration driven by international inequality is so huge that it could make nations as we know them obsolete. Both host countries and sendingsocieties may become multi-national; host countries may find themselves composed of many distinct societies co-existing but not inter-relating, while sending societies may become dispersed, with their economic center of gravity outside their country of origin. For neither would the country ofresidence coincide with national identity. Is this scenario likely, and does it matter?In Exodus, bestselling author Paul Collier tackles the emotive topic of international migration from the poorest countries. Framed by the triple perspective of the migrants themselves, the people left behind, and the host societies, Exodus is grounded primarily in Collier's own research, andpromises to bring new understanding to one of the most complicated and controversial topics of our time. Contrary to much previous economic analysis immigration, which has usually conflated the three perspectives and concluded that migration is beneficial because of the large gains to migrants themselves, Collier provocatively argues that nations are important and legitimate moral units on whichmigrants free-ride, and that national barriers can only be dissolved within severe limits. Exodus presents a case for the ethical legitimacy of restricting migration in the interests of both sending and receiving societies. Supporting his argument with case studies of those who are left behind,those who migrate to new countries, and those who feel the effects of immigrants into their societies, Collier offers a provocative analysis that will undoubtedly stir up much needed discussion of this complex topic.