In the Swiss debate about integration, opinions are divided about when foreign nationals should receive Swiss citizenship. Some people believe that immigrants should be naturalized as soon as possible to promote integration. Others think that naturalization should happen after many years to mark the successful integration of immigrants. In a study funded by the Swiss National Science Foundation (SNSF), IPL researchers have been able to show that the naturalization of immigrants is a catalyst for integration. It is particularly beneficial for foreigners who are part of a marginalized immigrant group at the time of naturalization, they found.

The researchers analyzed data from a controversial naturalization process that is no longer permitted today: the secret ballot on individual applications for naturalization, which was used in 46 local councils in German-speaking Switzerland between 1970 and 2003. On the basis of this quantitative database comprising 2225 applications, the researchers identified 768 people whose applications were either narrowly accepted or rejected. There are no significant differences between the two groups regarding their age, sex, language skills, number of years in Switzerland or country of origin. “In some cases, the difference between them was merely a few votes, which turned 49% into 51%. It was down to luck whether people received Swiss citizenship or not,” says IPL co-director Jens Hainmueller.

The researchers interviewed people whose applications were narrowly accepted or rejected, aiming to capture how well they had integrated after that decision. They asked questions such as: are you involved in politics? Do you read Swiss newspapers? Are you a member in a club or association? Do you feel discriminated against? Do you plan to spend your retirement in Switzerland?

The results show that migrants who became Swiss citizens by a narrow margin more than 15 years ago are much more integrated than migrants whose applications were narrowly rejected. The largest difference was found in the migrant groups most likely to face prejudice: People from former Yugoslavia and Turkey, as well as people not born in Switzerland, benefited most from naturalization.

The effects of naturalization are just as pronounced with regard to political integration: the political knowledge of people who were only narrowly naturalized rises to the level of people who were born Swiss. Migrants whose applications were narrowly rejected remain politically marginalized to this day.

“Our study shows that naturalization promotes social and political integration in the long term. The earlier a person receives citizenship, the greater the positive effect,” says IPL co-director Dominik Hangartner. This should be a wake-up call for Switzerland, he adds: “Migrants have to wait twelve years for naturalization, a long time compared to other European countries. Our study shows that a reduction of this waiting period would promote integration, and this would have a positive impact on society as a whole.”