A Longitudinal Analysis of Naturalization and International Migration in Switzerland, 2011-2017.

The notion of residential settlement associated with the acquisition of new citizenship has been recently challenged by a number of studies highlighting its instrumentality as a subsequent mobility factor. The long and diverse history of Switzerland as a country of immigration and the availability of rich data on naturalization and international migration that allow individuals to be followed over time make this country a valuable case for investigating the impact of naturalization on international (return or onward) migration. Using longitudinal data, we follow 88,900 immigrants who entered the country between 1998 and 2000 over a period of 84 months between January 2011 and December 2017, documenting changes in naturalization status and in migratory movements and their direction. Using different implementations of a Cox proportional hazards model, we examine whether and under what conditions the international migration behaviour of naturalized persons differs from that of non-naturalized persons. Our results show that the population accessing naturalization tends to be less mobile, but also that among third-country nationals, naturalization can trigger further international mobility, in particular among those with poor economic performance and with no family ties in Switzerland.