Farrell posits that the pay gap will be reduced or increased based on the parenting decisions made more than other single factor. "If women earn less than men for the same work, then when a man and woman get married, it makes sense for the woman to stay home and for the man to go to work," Farrell says. "But the deeper truth is that when women put the type of time and energy and flexibility into the workplace—like traveling overnight or going overseas or relocating—and the man becomes the raiser of the children, then women, from what I can tell, actually earn more than their male counterparts."
Executives, however, are generally past child-bearing years, so this doesn't easily explain why executives leave the workforce at higher rates than men. It may better explain why so few women become executives. (Also, some women may plan their careers in anticipation of fewer opportunities for promotion and high pay, and avoid shooting for executive positions.) In their working paper on executives, Gayle, Miller, and Golan consider the possibility that female executives leave because they may face more "unpleasantness, indignities, and tougher unrewarding assignments at work."
Much of the research into the gender wage gap has found that after other variables are controlled for, women still experience lower wages. Gender discrimination has typically been considered one possible explanation for the remaining gap. One recent study looking at more than 4,000 MBA graduates found that women grads earned an average $4,600 less than male grads in the first job out of graduate school. Men's first jobs were more likely to be at a higher rank, according to the study by Catalyst, a nonprofit that works to expand opportunities for women in business. Those findings held even when accounting for experience, industry, parenting responsibilities, and aspirations, according to the report, which was based on an online survey of nearly 10,000 alumni who graduated from international and domestic MBA programs between 1996 and 2007.
On Equal Pay Day last month, President Obama issued a proclamation that drew the larger implications of wage concerns: "Our nation's workforce includes more women than ever before. In households across the country, many women are the sole breadwinner, or share this role equally with their partner. However, wage discrimination still exists."