Rainer Munz is Professor of Demography at Humboldt University, Berlin. Until 1992 he was director of the Institute for Demography at the Austrian Academy of Sciences, Vienna. His main fields of interest are international migration, ethnic and linguistic minority issues and the impact of demographic change on social policy. Rainer Ohliger is a researcher within the interdisciplinary research project Gesellschaftsvergleich, based at Humboldt University. His main fields of research are historical migration, inter-ethnic relations and transition in Eastern and Central Europe.