Abstract
In this study we provide new evidence on the much-discussed effect of education on political participation by utilizing the quasi-experiment of twinning. By looking at the relationship between education and participation within monozygotic (MZ) twin pairs we are able to circumvent traditional sources of confounding of the relationship rooted in genes and early life family environment because MZ twins share both. The results of within-twin pair analyses based on surveys from the United States, Denmark and Sweden show that while the relationship between education and political participation is highly confounded by genes and/or familial environment in all three countries, a positive impact remains of years of education in the US and of high school completion in Denmark. No effect is found in Sweden. Robustness checks suggest that the observed effect is not confounded by within-twin pair differences in prenatal environment nor differential treatment during childhood, and, if anything, that it most likely constitutes a lower bound estimate.