More than a quarter of people aged 15–34 living in countries in the Organisation for Economic Co-operation and Development are foreign-born or have foreign-born parents. Immigration can expand the pool of skilled labor and boost innovation, but it also poses challenges in integrating people into the educational system, labor market, and society at large. Failure to integrate may increase inequality, social tension, and political backlash. Common elements of successful integration policies include an inclusive educational system, access to employment opportunities, and measures that foster language learning. Another important but controversial policy is access to host-country citizenship.

Granting citizenship to immigrants has been shown to increase their social integration, employment, and earnings, perhaps by incentivizing investment in host-country language skills, removing employment barriers, and mitigating discrimination. Research has also found that granting legal permanent resident status can reduce crime by increasing immigrants’ labor market opportunities. While research has primarily examined adult immigrants, a growing number of studies have investigated the consequences of granting citizenship at birth to children of immigrants. Our research examines the effects of such a reform on youth crime in Germany.

Germany is the only major immigrant-receiving country to have introduced birthright citizenship in recent decades. Prior to 2000, children born in Germany acquired citizenship at birth only if at least one parent was a German citizen. The Act to Reform Nationality Law, passed on July 15, 1999, introduced a conditional form of birthright citizenship. Under this new regime, children born in Germany on or after January 1, 2000, automatically acquired citizenship if at least one parent had legally resided in Germany for at least eight years at the time of birth. Parents could not opt out. Following the reform, the proportion of second- and third-generation immigrants born with citizenship increased from 22 percent to 89 percent in the three states covered by our analysis.

Our research uses administrative data on all police-reported criminal cases in the German states of Baden-Württemberg, Berlin, and Hesse. Together, these states comprise approximately 20.5 million residents, or about 25 percent of the German population, and rank among the states with the highest shares of immigrants. Our dataset contains detailed information on the date, location, and type of each offense, as well as the month of birth, gender, and citizenship status of suspects.

We compared German and non-German suspects born between July and December 1999 with those born between January and June 2000. Children in these groups typically attended school in the same grade, but the reform applied only to those born in the new millennium. Furthermore, we compared differences in youth crime between these groups with differences in crime among children born between July 1998 and June 1999. This allowed us to account for typical differences in youth crime by the month of a suspect’s birth, isolating differences caused by the reform. We considered all crimes committed by young people aged 14 years to 19 years and eight months, corresponding to offenses recorded between July 2012 and February 2020. We imposed this upper age limit to avoid confounding effects associated with COVID-19 lockdowns.

Our findings reveal a sharp decline in offenses committed by non-Germans born after the reform. This makes sense because the reform resulted in fewer immigrant children being born as non-Germans. If the reform did not affect youth crime, this decline should have been offset by a commensurate increase in offenses committed by Germans, as more immigrant children were now born as Germans due to the reform. However, the actual increase in offenses committed by Germans was smaller than the decline in offenses committed by non-Germans, suggesting that birthright citizenship reduced crime among immigrant children. Specifically, our calculations reveal a 70 percent reduction in youth crime among children who obtained citizenship because of the reform.

Our research finds that the reduction in youth crime was exclusively driven by boys, while girls demonstrated an increase in crime. This finding aligns with prior research showing that the reform reduced girls’ life satisfaction, integration, and educational achievement but had no comparable effects for boys, arguably because parents pushed their daughters to conform to traditional culture. However, since boys committed crimes at a much higher rate, they dominated the overall effect. Our research also breaks down the effects by type of crime and shows that the reduction in youth crime was driven by significant decreases in property and drug-related offenses.

Our research is particularly relevant given the ongoing debate in the United States over abolishing birthright citizenship. Our findings suggest that inclusive citizenship policies can reduce crime and its associated costs, which could strengthen social cohesion. Moreover, other research has shown that the German reform improved the educational outcomes of immigrant children and promoted their social integration.

Note
This research brief is based on Leander Andres et al., “Birthright Citizenship and Youth Crime,” National Bureau of Economic Research Working Paper no. 35070, April 2026.