The official Bureau of Labor Department statistics show that the median earnings of full-time female workers is 77 percent of the median earnings of full-time male workers. But that is very different than “77 cents on the dollar for doing the same work as men.” The latter gives the impression that a man and a woman standing next to each other doing the same job for the same number of hours get paid different salaries. That’s not at all the case. “Full time” officially means 35 hours, but men work more hours than women. That’s the first problem: We could be comparing men working 40 hours to women working 35.

But we’re still not close to measuring women “doing the same work as men.” For that, we’d have to adjust for many other factors that go into determining salary. Economists Francine Blau and Lawrence Kahn did that in a recent paper, “The Gender Pay Gap.”.”They first accounted for education and experience. That didn’t shift the gap very much, because women generally have at least as much and usually more education than men, and since the 1980s they have been gaining the experience. The fact that men are more likely to be in unions and have their salaries protected accounts for about 4 percent of the gap. The big differences are in occupation and industry. Women congregate in different professions than men do, and the largely male professions tend to be higher-paying. If you account for those differences, and then compare a woman and a man doing the same job, the pay gap narrows to 91 percent. So, you could accurately say in that Obama ad that, “women get paid 91 cents on the dollar for doing the same work as men.”

I believe that the remainder of the gap can be accounted for by looking at other voluntary factors that differentiate men and women.

The Heritage Foundation says that a recent study puts the number at 95 cents per dollar.

Excerpt:

Women are more likely than men to work in industries with more flexible schedules. Women are also more likely to spend time outside the labor force to care for children. These choices have benefits, but they also reduce pay—for both men and women. When economists control for such factors, they find the gender gap largely disappears.

A 2009 study commissioned by the Department of Labor found that after controlling for occupation, experience, and other choices, women earn 95 percent as much as men do. In 2005, June O’Neil, the former director of the Congressional Budget Office, found that “There is no gender gap in wages among men and women with similar family roles.” Different choices—not discrimination—account for different employment and wage outcomes.

A popular article by Carrie Lukas in the Wall Street Journal agrees.

Excerpt:

The Department of Labor’s Time Use survey shows that full-time working women spend an average of 8.01 hours per day on the job, compared to 8.75 hours for full-time working men. One would expect that someone who works 9% more would also earn more. This one fact alone accounts for more than a third of the wage gap.

[…]Recent studies have shown that the wage gap shrinks—or even reverses—when relevant factors are taken into account and comparisons are made between men and women in similar circumstances. In a 2010 study of single, childless urban workers between the ages of 22 and 30, the research firm Reach Advisors found that women earned an average of 8% more than their male counterparts. Given that women are outpacing men in educational attainment, and that our economy is increasingly geared toward knowledge-based jobs, it makes sense that women’s earnings are going up compared to men’s.

When women make different choices about education and labor that are more like what men choose, they earn just as much or more than men.