This past spring, the White House Council on Women and Girls released a much-anticipated report called Women in America. One of its conclusions struck a familiar note. As President Barack Obama put it: "Women still earn on average only about 75 cents for every dollar a man earns. That's a huge discrepancy."
It is a huge discrepancy. It's also an exquisite example of what journalist Charles Seife has dubbed "proofiness." Proofiness is the use of misleading statistics to confirm what you already believe.
Indeed, the 75-cent meme depends on a panoply of apple-to-orange comparisons that support a variety of feminist policy initiatives, from the Paycheck Fairness Act to universal child care, while telling us next to nothing about the well-being of women.
This isn't to say that all is gender-equal in the labor market. It is not. It also isn't to imply that discrimination against women doesn't exist or that employers shouldn't get more creative in adapting to the large number of mothers in the workplace. It does and they should.
But by severely overstating and sensationalizing what is a universal predicament (I'm looking at you, Sweden and Iceland!), proofers encourage resentment-fueled demands that no government anywhere has ever fulfilled -- and that no government ever will.
Let's begin by unpacking that 75-cent statistic, which actually varies from 75 to about 81, depending on the year and the study. The figure is based on the average earnings of full-time, year-round workers, usually defined as those who work 35 hours a week or more.
But consider the mischief contained in that "or more." It makes the full-time category embrace everyone from a clerk who arrives at her desk at 9 a.m. and leaves promptly at 4 p.m. to a trial lawyer who eats dinner four nights a week -- and lunch on weekends -- at his desk.
I assume, in this case, that the clerk is a woman and the lawyer a man for the simple reason that -- and here is an average that proofers rarely mention -- full-time men work more hours than full-time women do. In 2007, according to the Bureau of Labor Statistics, 27 percent of male full-time workers had workweeks of 41 or more hours, compared with 15 percent of female full-time workers; just 4 percent of full-time men worked 35 to 39 hours a week, while 12 percent of women did. Since full-time men work more than full-time women do, it shouldn't be surprising that the men, on average, earn more.
The other arena of mischief contained in the 75-cent statistic lies in the seemingly harmless term "occupation." Everyone knows that a CEO makes more than a secretary and that a computer scientist makes more than a nurse. Most people wouldn't be shocked to hear that secretaries and nurses are likely to be women, while CEOs and computer scientists are likely to be men. That explains much of the wage gap.
But proofers often make the claim that women earn less than men doing the exact same job. They can't possibly know that. The Labor Department's occupational categories can be so large that a woman could drive a truck through them. Among "physicians and surgeons," for example, women make only 64.2 percent of what men make. Outrageous, right? Not if you consider that there are dozens of specialties in medicine: some, like cardiac surgery, require years of extra training, grueling hours, and life-and-death procedures; others, like pediatrics, are less demanding and consequently less highly rewarded. Only 16 percent of surgeons, but a full 50 percent of pediatricians, are women.
Many studies have examined this subject, and a consensus has emerged that when you control for what researchers call "observable" differences -- not just hours worked and occupation, but also marital and parental status, experience, college major and industry -- there is still a small unexplained wage gap between men and women. Two Cornell economists, Francine Blau and Lawrence Kahn, place the number at about 9 cents per dollar. In 2009, the CONSAD Research Corp. located the gap a little lower, at 4.8 to 7.1 percent.
So what do we make of what, for simplicity's sake, we'll call the 7 percent gap?
You can't rule out discrimination, whether deliberate or unconscious. Many women say male bosses are more comfortable dealing with male workers. It's also possible that male managers fear that a female candidate for promotion, however capable, will be more distracted by family matters than a male would be. They might assume women are less able to handle competition and pressure. Even female managers may think such things.
No, you can't rule out discrimination. Neither can you rule out other, equally plausible explanations for the 7 percent gap. The data available to researchers may not be precise; for instance, it's extremely difficult to find accurate measures of work experience. There's also a popular theory that women are less aggressive than men when it comes to negotiating salaries.
The point is that we don't know the reasons for the 7 percent gap. What we do know is that making discrimination the default explanation, as proofers do, leads us down some weird rabbit holes.
Asian men and women earn more than white men and women, says the Bureau of Labor Statistics. Does that mean whites are discriminated against in favor of Asians? Female cafeteria attendants earn more than male ones do. Are men discriminated against in that field? Women who work in construction earn almost exactly what men in the field do, while women in education earn considerably less.
But across fields, women do work fewer hours, choose less demanding jobs and then earn less than men. Why? The answer is obvious: kids.
A number of researchers have found that if you consider only childless women, the wage gap disappears. June O'Neill, an economist who has probably studied wage gaps as much as anyone alive, has found that single, childless women make about 8 percent more than single, childless men do (though the advantage vanishes when you factor in education). Using Census data of pay levels in 147 of the nation's 150 largest cities, the research firm Reach Advisors recently showed that single, childless working women under 30 earned 8 percent more than their male counterparts.
That's likely to change as soon as the children arrive. Mothers, particularly those with young children, take more time off from work; even when they are working, they're on the job less. The Behind the Pay Gap study found that "among women who graduated from college in 1992--93, more than one-fifth (23 percent) of mothers were out of the work force in 2003, and another 17 percent were working part-time," compared with under 2 percent of fathers in each case.
The most compelling research into the impact of children on women's careers and earnings comes from a 2010 article in the American Economic Journal by Marianne Bertrand of the University of Chicago and Claudia Goldin and Lawrence Katz of Harvard.
The authors followed nearly 2,500 MBAs who graduated between 1990 and 2006 from the University of Chicago's Booth School of Business. They found that right after graduation, men and women had nearly identical earnings and working hours. Over the next 10 years, women fell way behind. Surveys revealed three reasons. First, men had taken more finance courses and performed better in them, while women had taken more marketing classes. Second, women had more career interruptions. Third and most important, mothers worked fewer hours.
MBA mothers, especially those with higher-earning spouses, "actively chose" family-friendly workplaces that would allow them to avoid long hours, even if it meant lowering their chances to climb the greasy pole. In other words, they bought tickets for the "mommy track."
A little over 20 years ago, the Harvard Business Review published an article by Felice Schwartz proposing that businesses make room for the many women who would want to trade some ambition and earnings for more flexibility and time with their children. Dismissed as the "mommy track," the idea was reviled by those who worried that it gave employers permission to discriminate and encouraged women to downsize their aspirations.
But as Virginia Postrel noted in a recent Wall Street Journal article, Ms. Schwartz had it right. When working mothers can, they tend to spend less time at work. This explains why female lawyers are twice as likely as men to go into public-interest law, in which hours are less brutal than in the partner track. Female medical students tell researchers they're choosing not to become surgeons because of "lifestyle issues," which seems a euphemism for wanting more time with the kids. Thirty-three percent of female pediatricians are part-timers -- and that's not because they want to play more golf.
In the literature on the pay gap and in the media, this state of affairs typically leads to cries of injustice. The presumption is that women pursue reduced or flexible hours because men refuse to take equal responsibility for the children and because the United States does not have "family-friendly policies." Child care is frequently described as a burden to women, a patriarchal imposition on their ambitions and a source of profound inequity.
But there is no evidence for either of these propositions. If women work fewer hours than men do, it appears to be because they want it that way.
About two-thirds of the part-time workforce in the United States is female. According to a 2007 Pew Research survey, only 21 percent of working mothers with minor children want to be in the office full-time. Sixty percent say that they would prefer to work part-time, and 19 percent would like to give up their jobs altogether. For working fathers, the numbers are reversed: 72 percent want to work full-time and 12 percent part-time.
In fact, women choose fewer hours -- despite the resulting gap in earnings -- all over the world. That includes countries with generous family leave and child-care policies.
Look at Iceland, recently crowned the world's most egalitarian nation by the World Economic Forum. The country boasts a female prime minister, a law requiring that the boards of midsize and larger businesses be at least 40 percent female, excellent public child care and a family leave policy that would make NOW members swoon. Yet despite successful efforts to get men to take paternity leave, Icelandic women still take considerably more time off than men do. They also are far more likely to work part-time. According to the Organization for Economic Cooperation and Development, this queen of women-friendly countries has a bigger wage gap -- women make 62 percent of what men do -- than the United States.
Sweden, in many people's minds the world's gender utopia, also has a de facto mommy track. The gender wage gap among full-time workers in Sweden is 15 percent -- lower than in the United States but hardly a feminist Promised Land.
The list goes on.
So it makes no sense to think of either the mommy track or the resulting wage differential as an injustice to women. Less time at work, whether in the form of part-time jobs or fewer full-time hours, is what many women want and what those who can afford it tend to choose.
Feminists can object till the Singularity arrives that women are "socialized" to think that they have to be the primary parent. But after decades of feminism and Nordic engineering, the continuing female tropism toward shorter work hours suggests that that view is either false or irrelevant. Even the determined Swedes haven't been able to get women to stick around the office.
That doesn't mean the mommy track doesn't present a problem, particularly in a culture in which close to half of all marriages break down. A woman can have a baby, decide to reduce her hours and her pay, forgo a pension and then, 10 years later, watch her husband run off with the Pilates instructor. The problem isn't what it used to be when women had fewer degrees and less work experience during their childless years; women today are in better shape to jump-start their careers if need be. The risk remains, however.
It's not at all clear how to solve this problem or even if there is a solution, especially during these fiscally challenged days. But one thing is clear: The wage-gap debate ought to begin with the mommy track, not with proofy statistics.
Kay S. Hymowitz is a contributing editor of City Journal, where this article first appeared, the William E. Simon Fellow at the Manhattan Institute and the author of "Manning Up: How the Rise of Women Has Turned Men into Boys."