HOW serious are we, really, about tackling income equality?

The Securities and Exchange Commission took a shot at it last week, approving a rule that would require companies to disclose their C.E.O. pay gap — comparing how much chief executive officers take home compared with ordinary employees.

That’s a fine idea. But here’s a better one: require companies to publish their gender pay gap.

Think about it. Calling out top executives for making too much money will at most embarrass a few suits. But calling out companies for paying women too little will help millions — and perhaps crack one of the most intractable problems of our time.

More than a half-century after President John F. Kennedy signed the Equal Pay Act of 1963, the gap between what men and women earn has defied every effort to close it. And it can’t be explained away as a statistical glitch, a function of women preferring lower-paying industries or choosing to take time off for kids.

Claudia Goldin, a labor economist at Harvard, has crunched the numbers and found that the gap persists for identical jobs, even after controlling for hours, education, race and age. Female doctors and surgeons, for example, earn 71 percent of what their male colleagues make, while female financial specialists are paid just 66 percent as much as comparable men. Other researchers have calculated that women one year out of college earn 6.6 percent less than men after controlling for occupation and hours, and that female M.B.A. graduates earn on average $4,600 less than their male classmates for their first jobs.