In recent decades, Europe has experienced periods of substantial immigration. Under the heading "replacement migration", this influx of people is sometimes discussed as a potential strategy for alleviating the negative effects of low fertility rates. It is the role of the political system to decide what rights should be extended to residents of foreign nationality, with the granting of citizenship being the most far-reaching option.

This section (collected until 2016 within PERFAR) provides legal information on policies over time, focusing on the following fields: