Story highlights Sabrina Schaeffer: Tuesday is Equal Pay Day, a fictitious holiday marked by progressive women

She says the wage gap between men and women is grossly overstated

Sabrina L. Schaeffer is the executive director of the Independent Women's Forum. The opinions expressed in this commentary are solely those of the author.

(CNN) Tuesday is Equal Pay Day, the fictitious holiday marked by progressive women's groups as the point in the year women would have to work to make up for "lost" wages as a result of the so-called wage gap.

In the wake of Hillary Clinton's presidential announcement, the "holiday" has special meaning. Clinton's election will no doubt center on women voters, and the Democratic women's agenda centers on pay equity and fairness in the workplace.

It's a comparison of averages -- comparing full-time working women with full-time working men -- that doesn't control for any of the important factors that go into determining one's salary such as education, profession, title, time spent in the workforce and time spent in the office each day, to name a few.

Sabrina L. Schaeffer

When we do control for these variables, a much smaller wage gap persists of about 4-6 cents, some of which may be the result of gender discrimination, but also is likely a function of women's choices and different behavior, such as not negotiating as often as men do -- factors for which economists simply can't control.

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