This book is the first interdisciplinary study of the fundamental normative issues underpinning immigration policy. Economists, political scientists, and philosophers address issues such as the proper role of the state in supporting a particular culture, the possible destabilisation of the political and social life of a country through immigration, the size and distribution of economic losses and gains, and the legitimacy of discriminating against potential immigrants in favour of members of the resident population. The need for serious philosophical consideration of this subject is beyond question. This volume should advance discussion in an area of great practical as well as philosophical importance.