The high school years (13 to 18 in Italy) are crucial for young women in shaping their preferences and self-confidence. In part, girls may shape those attributes by comparing themselves to male students. If there are fewer men for comparison, they may more readily consider themselves to be good at math, or interested in science, or fascinated by technology, attributes our society stereotypically assigns to men. Recent experimental research shows that gender-specific roles may be perpetuated at the high-school level (see Mobius et al. 2012 on how women and men adjust their beliefs about themselves). With fewer men around, some women are freer to choose to pursue what they love and what they are good at.
....If an objective of schooling is to increase women’s career opportunities and thereby their salaries, our results would suggest that gender-separated classrooms would be an effective step in the right direction. Incidentally, men will also benefit, being encouraged to enroll in high-earning majors. Gender-separated classrooms would increase the probability of choosing high-earning majors for both women and men.