Effectiveness and Spillovers of Online Sex Education: Evidence from a Randomized Evaluation in Colombian Public Schools

Sexual health problems cause negative externalities from contagious diseases and public expenditure burdens from teenage pregnancies. In a randomized evaluation, we find that an online sexual-health education course in Colombia leads to significant impacts on knowledge and attitudes and, for those already sexually active, fewer STIs. To go beyond self-reported measures, we provide condom vouchers six months after the course, and find a 9 percentage point increase in redemption. We find no evidence of spillovers to untreated classrooms, but we do observe a social reinforcement effect: the impact intensifies when a larger fraction of a student's friends is also treated.