International migration has rapidly grown and changed in composition in the last few decades. Countries of origin and destination have also become more diverse. Countries of destination have migration management and integration high in their policy agendas, while countries of origin put emphasis on protecting their citizens abroad and maintaining their bonds with them. The potential contribution that diasporas can make towards the development of their home countries is now fully acknowledged. The availability of high-quality and internationally comparable data on the size and characteristics of the migrant populations by country of origin is a prerequisite for proper analysis of migration as well as for the implementation of effective policies by countries on both sides of the migration phenomenon.