People move, individually and collectively, for a combination of economic, social, political and cultural reasons. The impact of migration on the individuals concerned, their families, the countries they leave and the societies they join raises issues that are hotly contested by academics, policymakers and politicians. By using a wide variety of analytical approaches the contributors to this book reveal the complexity and significance of this increasingly important phenomenon in Western European countries, which links these societies to the wider world. They engage directly with the challenge which human mobility represents by examining the reasons for migration, the contribution and needs of those migrating, and the ways in which public debate about migration may be manipulated for political reasons.