In this ground-breaking study, the issues and prospects of a multilateral response to the challenge of movements of people is explored. It presents, within a single, cohesive framework, the views, perceptions, and critical analyses of a group of eminent specialists drawn from different disciplines. It introduces the concept of an internationally harmonized migration regime, based on the principle of regulated openness—commonalty of policy objectives, harmonized normative principles, and co-ordinated institutional arrangements.