Virtually any commodity can move around the world to satisfy demand, but human beings have far less freedom. Many would-be migrants are forced to risk life and limb traveling illegally. Yet most rich countries are short of workers, have shrinking populations, and need more immigrants. This is a timely guide to a major issue that is never far from the political headlines.

Peter Stalker is a former co-editor of the New Internationalist who now works as a consultant to a number of UN agencies. He has written two books on migration for the International Labor Organization.