Comment on Causal Effects of Single-Sex Schools on College Entrance Exams and College Attendance : Random Assignment in Seoul High Schools

We re-examine the findings in Park, Behrman, and Choi (2012) regarding the causal effects of single-sex schooling on South Korean high school seniors’ performance in the college entrance examination and college attendance. The results with an extra year of data indicate that single-sex schools are more effective in improving test score than co-educational schools but not in raising four-year college attendance. We find no differences in academic outcomes of high school seniors between those in co-ed schools that use single-sex classrooms and those in co-ed schools that use co-ed classrooms. The effects of single-sex schooling are heterogeneous across school ownership types and gender, indicating some interaction effects of single-sex schooling with school and student characteristics. Thus, the positive effects of single-sex schooling on students’ academic outcomes are context-dependent