But we can, pretty confidently, answer a related question: How much of the pay gap is driven by those choices, and how much is driven by sexism in the workplace? The answer seems to be that almost all of the gap is driven by choice of occupation, and working hours, with an emphasis on working hours. Childless women who work the same hours as men make very close to what men do.

Does that mean there is no discrimination against women? No. The residual gap that’s left after you control for age, experience, work hours, choice of profession and so forth, is small. But it’s not zero. That residual most likely represents sexism. As a woman, I kind of take exception to that.

Most of the gap, however, seems to be driven by the fact that women work less, and that in many high-paying professions, how much you get paid is a function of how much you work … but not a linear function. There are outsized rewards to working the kinds of hours that make it very hard to care for a family.