In 2011, only 26% of workers in science, technology, engineering and math (STEM) fields were women, according to the U.S. Census Bureau.

A study released this April by the Institute for Women’s Policy Research, however, found that women earn less than men in almost every occupation – including male-dominated, female-dominated and gender-balanced fields.

Christianne Corbett, senior researcher at the American Association of University Women (AAUW), says Ma’s new findings are consistent with previous research done by AAUW, which found that men are more likely than women to boost their income by attending private colleges.

Corbett says this is likely because men from privileged backgrounds are able to better leverage the social networks they encounter at these schools.