Economist Claudia Goldin suggests that a bias against workplace flexibility is to blame:
Many companies still richly reward people who are available and work long, continuous hours, Goldin says. They give premium pay to certain key players – mostly men who don’t take time off for children or aging relatives. So women or men who need flexible schedules obtain them “at a high price, particularly in the corporate, finance and legal worlds,” Goldin writes in her paper. Technology and science fields are better off in pay equity, as are certain health care careers. … “It isn’t, quote, a women’s issue,” says Goldin in an interview with Quartz. The pay disparity shows up equally when male MBAs need reduced schedules or time off for personal or family needs.