Childhood exposure to coethnics increases naturalization.

In Europe, the tendency among immigrants and descendants to seek out and interact with other coethnics has raised concern for their integration as it can reduce contact with the ethnic majority. Though policymakers implement large-scale integration programs to counteract these trends, it remains empirically and theoretically ambiguous whether exposure to coethnic peers impedes integration, and causal evidence is more limited for the growing population of migrant children. In this article, I use high-quality Danish administrative panel data over 28 y to investigate whether the ethnic composition experienced in childhood among immigrants and descendants with a non-EU background affects a core behavioral indicator of integration: naturalization. To isolate the causal effect of the childhood ethnic composition, I use the quasi-experimental assignment of siblings into different school grades in the same school. I find that being exposed to coethnic peers in the school grade the probability of naturalizing later in life. The main explanation is that exposure to some coethnic peers improves academic skills which are positively correlated with citizenship acquisition. These findings demonstrate the causal importance of non-EU migrant children's social environment for their later integration into the national community showing that the modest presence of coethnic peers can be a precondition for, not a barrier to, integration.