This study examines the influence of exposure to older peers on sexual debut in urban South Africa. The study analyzes data from the Cape Area Panel Study (CAPS), a longitudinal survey of young adults in metropolitan Cape Town. The combination of early sexual debut, high school enrollment into the late teens, and high rates of grade repetition create an environment in which young people who progress through school ahead of their cohorts interact with classmates who may be several years older. We construct a measure of cumulative exposure to classmates at least two years older, and show that this measure has a statistically significant positive effect on sexual debut of adolescent girls. It also increases the age difference of the first sexual partner for those girls, and helps explain a significant fraction of the earlier sexual debut of African girls compared to coloured and white girls in Cape Town.
Country of focus: South Africa.