New study links immigrant naturalization to long-term political integration


Image of a woman holding her French naturalization decree.
A woman holds her French naturalization decree at a "Citizenship Welcome Ceremony."
Photo credit: 
REUTERS/Eric Gaillard

One of the key policy debates in Europe centers on how best to integrate immigrants. The issue is particularly salient in Switzerland where immigrants make up almost 25% of the population. New research from scholars at Stanford and the University of Zurich demonstrates that naturalization substantially improves the political integration of immigrants.

Jens Hainmueller, faculty affiliate of The Europe Center and co-director of the Immigration and Integration Policy Lab, along with his co-authors Dominik Hangartner and Giuseppe Pietrantuono, use an innovative research strategy to show that naturalization serves as a catalyst for integration.

Between 1970 and 2003 residents decided on naturalization applications in secret ballot referendumsin some Swiss municipalities. The researchers compare immigrants who just barely won a referendum with those that just barely lost, and the resulting natural experiment provides a treatment and control group that are almost identical.

"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 Hainmueller.

And because the researchers were able to survey immigrants 15 years after their naturalization decisions, the study provides one of the first unbiased estimates of the causal impact of naturalization on the long-term integration of immigrants.

In Switzerland, where immigrants must wait twelve years to apply for citizenship, the study suggests that reducing this waiting period could improve immigrant integration and positively impact Swiss society.

The full article is located on the Proceedings of the National Academy of Sciences website.

A recent news article on this research can be found in the October 22, 2015 Stanford Report