Marek Okólski is a professor at the Centre of Migration Research (CMR) at the University of Warsaw (Poland) and honorary chair of its Scientific Council. He founded the CMR in 1993 and served as its director until 2016. From 2010 to 2018, he was chair of the Committee for Migration Research at the Polish Academy of Sciences. For many years, he was also a member of the Government Council for Population and served as an adviser or expert in various other government and parliamentary bodies. His academic work includes lecturing and research at universities and institutes around the world. Professor Okólski has frequently been appointed as an expert by numerous international organisations (the UN, the European Commission, the World Bank, the Council of Europe, the OECD, the ILO and the IOM). He was deeply involved in initiating, in the early 1990s, the collaboration of researchers from Central and Eastern Europe within the mainstream of migration research, particularly within the IMISCOE network.Professor Okólski’s main areas of research are development economics and demography. Recently, he has focused primarily on international migration. His publications include over 300 academic articles and 20 books (in this number the editing or co-editing of three previous volumes in the IMISCOE Research series: International Migration in Europe. New Trends and New Methods of Analysis, 2008; A Continent Moving West. EU Enlargement and Labour Migration from Central and Eastern Europe, 2010 and European Immigrations. Trends, Structures and Policy Implications, 2012).