The Effect of Classroom Gender Composition on College Enrollment in STEM Fields

This study uses longitudinal data from mock examinations administered to high school students in 12 schools in Saitama Prefecture to examine how the percentage of female students in a class affects STEM-specializations and subsequent college enrollment. The results show that the effect of the ratio of female students varies before and after the institutional reallocation of peer groups induced by the academic tracking decision at the beginning of the second year of high school. During the pre-tracking period, a higher female ratio is associated with a higher likelihood that female students drop out of STEM specializations. In contrast, after tracking, this relationship reverses: female students in classes with a higher female ratio are more likely to persist in STEM specializations. This pattern is observed consistently among female students but not clearly among male students. These findings suggest that high school students’ educational choices are shaped not only by academic ability and relative rank, but also by social interactions such as role model effects and conformity pressures. Furthermore, the classroom female ratio influences not only students’ aspirations during high school but also their actual college enrollment outcomes.