Employers aren't supposed to discriminate when they pay male and female employees, but the Republicans are happy to leave things to chance by blocking the Paycheck Fairness Act. While that act would have closed loopholes and helped prevent pay discrimination, the NY Times looks at how there's another factor, aside from overt discrimination, that may be inhibiting women's earnings: Having children. It's a perfect complement to its story from a few days ago: Having children and being a lady entrepreneur is hard!

According to the Times, "Most economists believe the gap between women’s and men’s wages does not stem primarily from employers paying women less than men for the same job. It occurs mostly because men and women take different jobs and follow different career paths." For instance:

The economists Claudia Goldin and Lawrence F. Katz of Harvard University, and Marianne Bertrand of the University of Chicago, tracked the career paths of nearly 3,000 M.B.A.’s who graduated from the University of Chicago over 15 years, as they began their careers in business and finance. The women started off making 88 percent as much as men, on average. But 10 to 15 years later, they were making only 55 cents for every dollar of men’s pay.

After accounting for a number of differences, from grades to course choices, the economists concluded that women’s pay deficit was almost entirely because they interrupted their careers more often and tended to work fewer hours. The rest was mostly explained by career choices: for instance, more women worked at nonprofits, which pay less.

Their study points out that some women gravitate toward "veterinary medicine or pharmacy, [where] changes like business consolidation and technological progress have allowed for flexible and predictable schedules without a big drop in pay. For instance, among pharmacists there is no unexplained gender pay gap, Ms. Goldin said. Women earn less only if they work fewer hours. And women have flocked to those jobs."

The issue of motherhood, careers, and women's roles in contributing their families' incomes has become a hot topic this election year, with a Democratic strategist scoffing about Mitt Romney's accessibility with regular people and noting that his wife, stay-at-home mother-of-five Ann Romney has "never worked a day in her life." Ann Romney responded, "I made a choice to stay home and raise five boys. Believe me, it was hard work," but neglected to mention that she was able to stay at home because her husband cashed thousands he received in stock (from his father) and because Mitt wanted her to. So, ladies, keep debating about the mythological work-life balance, "motherhood penalty" and having it all.