Though past studies have found little evidence that women are opting out of the workforce in general, female graduates of elite undergraduate universities are working much fewer hours than their counterparts from less selective institutions, according to first-of-its-kind research out of Vanderbilt University.

“Even though elite graduates are more likely to earn advanced degrees, marry at later ages and have higher expected earnings, they are still opting out of full-time work at much higher rates than other graduates, especially if they have children,” said Joni Hersch, the study’s author and Vanderbilt professor of law and economics.