Not mixing genders in high-school classes = long-run gains

In most European and North American countries women have overtaken men in college graduation rates. Nevertheless, a striking gender gap persists in the salaries of men and women, even when they are highly educated – and even if the overall gap has, in fact, narrowed in some nations (Black and Spitz-Oener 2007). One important reason for that gap is that men and women choose different college majors leading to very different careers. Nearly two thirds of all humanities degrees are awarded to women. Men, instead, choose majors in engineering, economics and in the mathematical sciences in much larger proportions. In the US, about 80% of recent graduates in engineering were male. In turn, the choice of college major correlates strongly with earnings and career opportunities. For example, in 2011, US students of engineering had an average yearly salary of almost $55,000 after graduation. Newly minted graduates from humanities majors instead earned only about $31,500.
New evidence

A recent study The long-run gains of not mixing genders in high-school classes (Anelli and Peri 2013) asks if the gender composition of the high-school class attended by an individual affects his/her choice of study program and subsequent long-term earning potentials. The study uses data collected on 30,000 students in Italian high schools over the period 1985-2005, including information on their high school, college career, family background and income as of 2005.

The study finds that the gender ratio of high-school classmates significantly affected their choice of college major. In particular, women who attended a high-school class with a significant larger percentage of other female students (more than 75%) were significantly more likely to go on to choose college majors leading to high-paying jobs, namely engineering, economics, business and medicine. Those are also majors typically dominated by male students.

On the other hand, female students in classes with a balanced gender mix were more likely to choose typically ‘female’ majors, that is, largely in the humanities and arts, and leading to lower earnings and limited overall career potential.