This International Encyclopedia of Migration will define and explicate terms, concepts and key topics with widespread usage and recurring relevance for learning about and developing the fields of both international and internal migration. With migration being partly defined in the modern era by law and public policy, the subject includes knowledge not only from these areas but also from a full array of academic disciplines. Hence, this encyclopedia will include material from such fields as anthropology, archaeology, criminology, demography, economics, education, ethnic studies, geography, health sciences, history, law, linguistics, public policy, political science, psychology and sociology. As migration has been such an important part of the