Girls in Cape Town receive significantly less education if they are raised with sisters compared to those who are not.
April 25, 2026
Original Paper
THE EFFECT OF SIBLING SEX COMPOSITION ON FEMALE EDUCATION AND EARLY FERTILITY: EVIDENCE FROM CAPE TOWN, SOUTH AFRICA
SSRN · 6577020
The Takeaway
The gender makeup of a family has a profound and asymmetric effect on a child's future. While the sex of siblings has no impact on a boy's educational path, it creates a sister penalty for girls. This dynamic suggests that families with multiple daughters may be prioritizing resources in a way that disadvantages them. It reveals a hidden household friction where girls must compete for opportunities that are more freely given to their brothers. We often assume that poverty affects all children in a family equally. The data proves that gender dynamics inside the home can create vastly different futures for siblings.
From the abstract
<p><strong>Why does having sisters reduce a girl's chances of finishing school?</strong></p> <p>In Cape Town, South Africa, the sex of your siblings may quietly determine the course of your life. Using rich longitudinal data from the Cape Area Panel Study, tracking hundreds of adolescents through the critical transition from youth to adulthood, this paper uncovers a striking asymmetry: the sex composition of one's siblings shapes educational trajectories for young women, but leaves young men ent