Taking an active part in society is probably one of the best indicators of integration. It shows how far down the road an immigrant has come towards settling in and broadening involvement beyond material necessity. It is a marker of integration in the sense that it shows the interest that migrants hold for the functioning of their society and their ability and willingness to express their voice. Dimensions to gauge the extent to which migrants feel involved in society include involvement in broad voluntary societal activities, which might include membership and participation in associations, volunteer work, and, where by choice, enrolment in trade unions or political parties. Political participation is one dimension of implication in society. However, this dimension concerns only immigrants who have the citizenship of the country of residence. The degree of confidence in institutions, such as schools, police, and justice is closely related to one’s willingness to take an active part in the society. Citizenship is also a key determinant, as foreigners do not always have the same civic rights as citizens. Socio-demographic characteristics, such as age, income and education play a role. Immigrants who have lived in the country longer are more likely to participate in civic activities. Language proficiency is also a factor, since it determines the ability to express one’s voice in the public debate.In this chapter, the acquisition of nationality is examined (both in terms of stocks and flows, Indicator) as well as the participation in voting for those who have acquired the nationality of the host country (Indicator). For a discussion on these indicators, refer to the section Measurement at the end of this chapter.