Importantly, women who are continuously employed (ie "stayers") switch firms just as often as men — but don’t move *up* as much.

In their 40s and 50s, that changes: once care burdens ease, women start making *more* upward moves than men, once these constraints are released.

Interestingly, churn (moving in and out of employment) is common — but men and women do it at similar rates. Women just land in lower-paying sectors such as education, retail, or personal care, and in lower-paying firms *within* sectors.

The gap isn’t mainly about occupations or even bargaining within firms — it’s about women being firms that pay *all* workers less.

Using tax data on the full formal workforce, we find the gender gap in "firm pay” grows rapidly during women’s 30s — child-rearing years — then narrows later.