Stephen Castles is Professor and Director of the Centre for Multicultural Studies at the University of Wollongong, Australia and the author of The Age ofMigration: International Population Movements in theModern World. Alastair Davidson is Professor of Politics at Monash and Inaugural Professor of Citizenship Studies, Swinburne University of Technology, Melbourne, Australia. He is currently a Professorial Fellow at the Institute for Advanced Study, in Princeton, New Jersey.