Robin Cohen is Professor Emeritus of Development Studies and Senior Research Fellow, Kellogg College, University of Oxford. His books include The new helots: migrants in the international division of labour (1987, 1993, 2003), Frontiers of identity (1994), Global diasporas: an introduction (1997, 2008), Global sociology (co-author, 2000, 2007, 2013), Migration and its enemies (2006), Encountering difference (co-author, 2016) and Migration: the movement of humankind from prehistory to the present day (2019). He has edited or co-edited 21 further volumes, particularly on the sociology and politics of developing areas, diasporas, international migration, transnationalism and globalization. He directed the International Migration Institute, part of the Oxford Martin School (2009-2011) and was principal investigator on the Oxford Diasporas Programme funded by the Leverhulme Trust (2011-2016). Nicholas Van Hear is a researcher at the Centre on Migration, Policy and Society (COMPAS), at the University of Oxford. With a background in anthropology and development studies, he works on forced migration, conflict, development, diaspora, transnationalism and related issues, and has field experience in Africa, the Middle East, South Asia, North America and Europe. His books include New diasporas: the mass exodus, dispersal and regrouping of migrant communities (1998), The migration-development nexus (2003), and Catching fire: containing forced migration in a volatile world (2006). His main conceptual contributions have been on force and choice in migration; migration and development; diaspora formation and engagement in conflict settings, including post-war recovery; and migration and class.