Biblioteca

Women remain significantly underrepresented in Science, Technology, Engineering, and Mathematics (STEM) fields. We examine whether the ability of male and female college peers contributes to this gap. Using administrative data from Chile covering 33 universities and over 100 college majors, we exploit variation in peer composition across cohorts within programs (college major-university combinations) to identify causal effects. We track long-term outcomes including graduation, labor market performance, fertility, and marriage. Our results reveal substantial peer ability effects specific to women in STEM. Higher-ability female peers increase women’s probability of graduating from STEM programs, while higher-ability male peers decrease it. In the longer run, higher-ability male peers also reduce women’s employment, earnings, and work experience, while higher-ability female peers reduce fertility. We find no comparable effects for women in non-STEM fields or for men. These findings reveal that the ability of male versus female peers plays a critical role in shaping women’s outcomes specifically in STEM environments.