Do national identification and interethnic friendships affect one another? A longitudinal test with adolescents of Turkish origin in Germany

► I examine the association of national identification and interethnic friendships. ► Three-wave German panel data are used to disentangle the causal interplay. ► Special attention is paid to unobserved heterogeneity and reverse causality. ► National identification and interethnic friendships do not affect one another. ► The results imply that the association is caused by unobserved joint determinants.