Book excerpt: Migration has become an increasingly important phenomenon for European societies. Patterns of migration flows can change greatly over time, with the size and composition of migrant populations reflecting both current and historical patterns of migration flows. Combined with the complexity and long-term nature of the migrant integration process, this can present challenges to policy-makers who need good quality information on which to base decisions. It is important that the statistics should go beyond the basic demographic characteristics of migrants and present a wider range of socio-economic information on migrants and their descendants. This publication looks at a broad range of characteristics of migrants living in the European Union and EFTA countries. It looks separately at the foreign-born, the foreign citizens, and the second generation. It addresses a variety of aspects of the socio-economic situation of migrants including labour market situation, income distribution, and poverty. The effects of different migration-related factors (i.e. reason of migration, length of residence) are examined. The situation of migrants is compared to that of the non-migrant reference population.