Naturalisation promotes integration


Migrants are better integrated in the long term if they are naturalised. This is the conclusion reached by an SNSF-funded project.

In the Swiss debate about integration, opinions are divided about when foreign nationals should receive Swiss citizenship. Some people believe that immigrants should be naturalised as soon as possible to promote integration. Others think that naturalisation should happen after many years to mark the successful integration of immigrants. In a study funded by the Swiss National Science Foundation (SNSF), researchers at the universities of Zurich, Stanford and Mannheim have been able to show that the naturalisation of immigrants is a catalyst for integration. It is particularly beneficial for foreigners who are part of a marginalised immigrant group at the time of naturalisation. In this study, the people who benefited most were from Turkey and former Yugoslavia.

The researchers analysed data from a controversial naturalisation process which is no longer permitted today: the secret ballot on individual applications for naturalisation in 46 local councils in German-speaking Switzerland between 1970 and 2003. On the basis of this quantitative database comprising 2225 applications overall, 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 Professor Jens Hainmueller of Stanford University.

Long-term effect for integration

The researchers interviewed people whose applications were narrowly accepted or rejected by telephone. 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 faced with the most prejudices: "Our analysis shows that people from former Yugoslavia and Turkey as well as people not born in Switzerland benefited most from naturalisation," says Giuseppe Pietrantuono of the University of Zurich.

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

"Our study shows that naturalisation promotes social and political integration in the long term. The earlier a person receives citizenship, the greater the positive effect," says Dominik Hangartner, political scientist at the University of Zurich and the London School of Economics. This should be a wake-up call for Switzerland, he adds: “Migrants have to wait twelve years for naturalisation, 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."

(*) Jens Hainmueller, Dominik Hangartner, and Giuseppe Pietrantuono (2015). Naturalization Fosters the Long-Term Political Integration of Immigrants. Proceedings of the National Academy of Sciences. doi: 10.1073/pnas.1418794112

(journalists can obtain a pdf file from the SNF by writing to:

(*) Jens Hainmueller, Dominik Hangartner, and Giuseppe Pietrantuono (2015). Catalyst or Crown: Does Naturalization Promote the Long-Term Social Integration of Immigrants. SSRN Working Paper Series:


Dominik Hangartner
Department of Methodology
London School of Economics
Columbia House
London WC2A 2AE
Tel (Monday from 3 pm): +41 44 634 58 38
Tel (Thursday-Friday): +44 20 7955 6982

For more information about the project: