Marcel Erlinghagen is Professor of Sociology at the Institute for Sociology, University of Duisburg-Essen, Germany. He is also Research Fellow of the German Institute for Economic Research (DIW) in Berlin, Germany. In the past, he received research grants from the German Research Foundation (DFG), the Fritz-Thyssen-Foundation as well as from different government departments in Germany. In his research, he focuses on questions of migration and integration as well as on questions regarding labour market mobility, job security, and volunteering. His research has been published in leading international journals such as European Sociological Review, Journal of European Social Policy, Population Space and Place, Social Indicators Research, European Societies, and Journal of Social Policy.Andreas Ette is Head of the Research Group International Migration at the Federal Institute for Population Research in Wiesbaden, Germany. He was PhD Fellow at the Bielefeld Graduate School in History and Sociology (BGHS) and guest researcher at the European University Institute. His research interests include the sociology and the politics of international migration in Europe. A particular interest in his recent research is directed towards the consequences of international migration for the individual life course as well as the responses of public administrations towards migration and diversity. His work has been published in the Journal of International Migration and Integration and the Educational Research Review.Norbert F. Schneider is Director of the Federal Institute for Population Research, Germany. Previously, he was professor of sociology at the Johannes-Gutenberg University of Mainz, Germany and co-director of the State Institute for Family Research at the University of Bamberg, Germany. He teaches as a guest professor and honorary professor at the Universities of Vienna, Frankfurt, and Mainz. He is author and editor of various academic journals and book series and fulfils functions in national and international academic associations. Nils Witte is Research Fellow at the Federal institute for Population Research, Germany. Previously, he was postdoctoral researcher in a DFG-funded project dealing with occupational closure and wage inequality at the Karlsruhe Institute of Technology. He obtained his PhD from the Bremen International Graduate School of Social Sciences and was DAAD-funded guest researcher at the European University Institute. His research interests include international migration, social closure, labour market outcomes, and empirical research methods. His work has been published in the Journal of Ethnic and Migration Studies and European Sociological Review.