Does the number of sex partners affect educational attainment? Evidence from female respondents to the Add Health

We use data on young women from the National Longitudinal Study of Adolescent Health to explore the relationship between number of sex partners and educational attainment. Using the average physical development of male schoolmates to generate plausibly exogenous variation in number of sex partners, instrumental variables estimates suggest that number of sex partners is negatively related to educational attainment. This result is consistent with the argument that romantic involvements are time consuming and can impose substantial emotional costs on young women.