April 14 is feminists’ misconceived Equal Pay Day.

That’s the day of the year, they say, when all women’s wages, allegedly only 78% of all men’s, “catch up” to what men have earned the year before. The fairy tale is that women have to work those extra months to get their fair share.

Feminists want Congress to pass the Paycheck Fairness Act, introduced in this Congress on March 25 by Maryland Sen. Barbara Mikulski and Connecticut Rep. Rosa DeLauro, both Democrats. The bill, which would insert government even further into firms’ compensation decisions, did not even pass the 111th Democratic Congress in 2009-2010, even though President Obama would have signed it into law.

Tomorrow is the day that the well-funded feminist machine will spring into action. The National Committee on Pay Equity (NCPE) has an online “equal pay day kit,” with a sample letter to the editor, a sample op-ed that feminists can send to local newspapers and a sample news advisory. The NCPE advises women to do “anything to encourage editors to send a photographer. Mention any sound effects — a song or a slogan that women will chant to encourage radio attendance.”

The American Association of University Women offers women Advocacy How-to Guides for Equal Pay Day, including instructions on how to put together an issue forum and how to get the whole world to sign a petition. It wants government-funded child care and laws on employer-provided medical and sick leave.

“ American women are winners, although it’s hard to believe from the Equal Pay Day rhetoric. ”

To see the politicization of the equal-pay issue, look no further than the White House, where female staffers are paid 87% of the earnings of male staffers. Still, feminists don’t complain. Attacking the White House for its pay gap is not in the advocacy materials of the AAUW or the NCPE.

American women are winners, although it’s hard to believe from the Equal Pay Day rhetoric. Department of Education data show that in 2012, the latest available, they earned 57% of bachelor’s degrees, 60% of master’s degrees and 51% of doctorates, as well as almost half of doctor of medicine and law degrees. The unemployment rate for adult women, at 4.9%, is now lower than that for adult men, at 5.1%.

The latest figures show that comparing men and women who work 40 hours weekly yields a wage ratio of 90%, even before accounting for different education, jobs or experience, which brings the wage ratio closer to 95%. Many studies, such as those by Professor June O’Neill of Baruch College and Professor Marianne Bertrand of the University of Chicago, show that when women work at the same jobs as men, with the same accumulated lifetime work experience, they earn essentially the same salary.

Some people are paid less than others because of the choices they make about field of study, occupation and time on the job. Compared with men, women tend to choose more college majors in the lower-paid humanities rather than in the sciences, and take more time out of the workforce for child-raising.

The Equal Pay Act of 1963 already requires equal pay for equal work, and the Lilly Ledbetter Fair Pay Act changed Title VII of the Civil Rights Act to allow workers to argue that their current compensation flows from discriminatory decisions made years back, with no statute of limitations.

But feminists want still more, and the Paycheck Fairness Act would allow women to sue for unlimited compensatory and punitive damages. It would encourage class actions by requiring workers who do not want to participate to opt out, rather than opt in, a radical change from conventional law and practice. The Equal Employment Opportunity Commission would collect data on the race, sex and wages of workers to test for and prevent discrimination.

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Feminists call for the government to set wages, rather than leaving this valuable function to the private sector, because the private sector does not do it adequately. It’s not fair, say feminists, that social workers, mostly women, earn less than oil drillers, almost all men — even though drilling for oil is a more dangerous profession.

Consider a large firm such as Royal Dutch Shell RDS.A, -2.24% . Under the Paycheck Fairness Act, would it have to pay clerical workers, mostly women, as much as it pays drillers on oil rigs? With such “equality,” who would be willing to work at the distant, more dangerous jobs in Alaska?

Wages change constantly and job classifications are imperfect, and can be changed. Some people work harder than others, and so deserve faster promotions and higher pay. Many women prefer to combine work with family, and choose lower-paying professions that allow more time at home.

This week feminists will hold rallies telling the world that women are underpaid, and calling for passage of legislation that would insert the government into firms’ compensation decisions. Don’t believe them. Women in America are doing better than men.