By Claire Cain Miller, The New York Times, May 13, 2017

When men and women finish school and start working, they’re paid pretty much equally. But a gender pay gap soon appears, and it grows significantly over the next two decades.

So what changes? The answer can be found by looking at when the pay gap widens most sharply. It’s the late 20s to mid-30s, according to two new studies — in other words, when many women have children. Unmarried women without children continue to earn closer to what men do.