90% of moms not coming back is an exaggeration for the bay area.

Part of what we're not talking about here (in this whole thread) is the cost of child care. Child care in SF is over $1700 a month, and hard to find for 3 month olds, which is why a lot of parents quit after leave.

I reckon we'll get a lot more parents staying in the workforce if the government helped more with childcare across all income ranges. Childcare comes at a lower income time of life, often when around when people have recently purchased a home.

We're also likely to have fewer parents drop out of the workforce if they can get their infants to 6+ months with a parent. Childcare is easier to find for 6 month olds than 3 month olds.