Political Selection and the Relative Age Effect

We present substantial evidence for the existence of a bias in the distribution of births of leading US politicians in favor of those who were the eldest in their cohort at school. The result is robust to both parametric and nonparametric tests and is not driven by measurement error, redshirting or a sorting effect of highly educated parents. The magnitude of the effect we estimate is larger than what other studies on 'relative age effects' find for broader (adult) populations, but is in general consistent with research that looks at high-competition environments. The findings are in line with a multiplier effect of early human capital acquisition (Cunha and Heckman, 2007) whereby early skill accumulation lowers the cost of further investments.