As much as feminists love to parrot the statistic that women earn only 76 cents on the male dollar, they rarely bother to provide an explanation or solid evidence for this claim. But fortunately a smart new book has hit the shelves just in time for Equal Pay Day to help them out.

Equal pay for equal work has been enforced by the Equal Employment Opportunity Act since it was made law in 1972. The Equal Pay Act of 1963 and Title VII of the Civil Rights Act of 1964 also ban sex-based wage discrimination. So it seems pretty remarkable that the wage gap is so wide and pervasive even today. Attorneys should be having a field day with class-action lawsuits. But they are not. Could it be that even the legal establishment is complicit in this glaringly obvious patriarchal conspiracy?

The 76-cent statistic (now actually 80 cents, according to the U.S. Census Bureau) is misleading because it is a raw comparison of all working men and women. Thus a female receptionist working 40-hour weeks is tossed in with the male orthopedic surgeon putting in 70-hour weeks.

A study of the gender wage gap conducted by economist June O’ Neill, former director of the Congressional Budget Office, found that women earn 98 percent of what men do when controlled for experience, education, and number of years on the job.

Warren Farrell, three-time board of directors member of the National Organization for Women New York City, exhaustively debunks the wage gap myth in his book “Why Men Earn More.” Farrell documents occupations requiring bachelor’s degrees in which women’s starting salaries actually exceed men’s. Female investment bankers and dieticians, for example, can expect to earn 116 percent to 130 percent of their male counterparts’ salaries.

The real reason than men tend to out-earn women is the choices they make. Men are far more likely to take unpleasant and dangerous jobs, what Farrell calls the “death and exposure professions.” For example, firefighting, truck driving, mining and logging — to name just a few high-risk jobs — are all more than 95 percent male. Conversely, low risk jobs like secretarial work and childcare are more than 95 percent female.

Farrell points out that in California, prison guards can earn $70,000 per year plus full medical benefits and retire after thirty years with a hefty retirement package. But it takes little imagination to figure out why California still has a difficult time staffing its prisons, and it goes without saying that most prison guards are male. Says Farrell, “As with most jobs, there’s an inverse relationship between fulfillment and pay.”

Because men are more likely to take jobs that are unpleasant, dangerous or dull in exchange for higher pay, they reap the financial benefit. Farrell summarizes this phenomenon this way: “Jobs that expose you to the sleet and the heat pay more than those that are indoors and neat.”

Another reason women’s average earnings are less than men’s is that they take more time out of the workforce for care-giving. Women, more so than men, adjust their work schedules to accommodate their families, and in poll after poll, they express a preference to do so.

“Well, why can’t men and women share domestic responsibilities 50-50 so women will be just as free and unencumbered as men are?” the conventional feminist argument goes. Such an arrangement is unrealistic as it requires both husband and wife to work part-time. Couples typically find it easiest for each partner to specialize and make the sacrifices required to sustain the family.

Scholars can debate whether it is societal pressure or innate desire that makes women elect to spend more time with their children. But so long as these decisions are a reflection of women’s expressed preferences, this isn’t a problem that needs to be solved.

Arrah Nielsen is a junior fellow at IWF.