Rich Lowry

To paraphrase the line often attributed to Mark Twain, there are lies, damn lies and the “equal pay” statistic.

The factoid that women earn only 77 cents of every dollar earned by men is the focal point of a feminist cargo cult. It has its own movement and its own quasi-holiday, the so-called Equal Pay Day, marking how far into a new year women supposedly have to work to match what men made the prior year. The figure is presumed to clinch any debate over the continued existence of massive discrimination against women in the workforce.

Drawn from Census Bureau data, the 77-cent stat is a compar...