Citizenship brings many benefits to immigrants and to their country of settlement, and represents a dynamic policy vehicle for promoting the political incorporation of immigrants and, by extension, their more complete integration. Naturalization allows immigrants to participate fully in the civic life of their new country, and is a powerful symbolic gesture of their commitment to their host society. The research collected here examines citizenship policies in a number of countries, the economic effects of citizenship, dual citizenship, citizenship by descent or birth in the territory, and the application and processing of citizenship applications.