Dual citizenship is a fact of life in a mobile world. As a result of international migration, rearrangements of the territorial scope of states, and the lack of a global coordination between citizenship laws, millions of people worldwide are citizens of two, or more, states. Children, in most cases, automatically become dual citizens when their parents are citizens of different states. They often also acquire two citizenships when they are born in another country than their parents, whose citizenship they acquire by descent, and their country of birth has a regime of territorial birthright. Many people moreover acquire an additional citizenship at a later stage of life because they take up residence in another country than where they born and wish to consolidate their position in that new society through acquiring the citizenship of their country of residence. Despite its ascendency as a demographic phenomenon, however, dual citizenship is still seen by many as a problematic phenomenon that should be avoided if possible. Many states, in Europe and beyond, actively discourage multiple citizenship, by requiring candidates for naturalization to renounce their previous citizenship prior to naturalization or by having provisions that lead to the automatic loss of citizenship when their citizens voluntarily acquire another citizenship. Yet, whereas dual citizenship at least in some countries is hotly debated, we know very little about whether having two or more citizenships matters in terms of the integration in host societies, for example in terms of participation by immigrants in the labor market, social contacts, and engagement in society.

The papers in this session focus on specifically on the category of persons for whom dual citizenship is most strongly contested: foreign-born immigrants. The papers discuss both the relation between the availability of dual citizenship and naturalization rates, as well as the relation between citizenship status and indicators of immigrant integration. The session has a strong comparative dimension, with papers focusing on the Netherlands, Sweden and the US. We also discuss important methodological questions about how best to analyze the relation between naturalization, dual citizenship and immigrant integration.