The Effect of Single-Sex Education on Test Scores, School Completion, Arrests, and Teen Motherhood: Evidence from School Transitions

In 2010, the Ministry of Education in Trinidad and Tobago converted 20 low-performing secondary schools from coeducational to single-sex. I exploit these conversions to identify the causal effect of single-sex schooling holding other school inputs constant. After also accounting for student selection, single-sex cohorts at conversion schools score higher on national exams and are four percentage points more likely to complete secondary school. There are also important non-academic effects; all-boys cohorts have fewer arrests as teens, and all-girls cohorts have lower teen pregnancy rates. These benefits are achieved at zero financial cost. Survey evidence suggests that these single-sex effects reflect both direct gender peer effects due to interactions between classmates, and indirect effects generated through changes in teacher behavior.