Some men see things as they are and ask why. Others dream things that never were and ask why not. Shaw

The average woman is born with around 300,000 eggs … 12 percent of those eggs remaining at the age of 30, and only 3 percent left by 40. … From the mid-30s on, the decline in fertility is much steeper with each passing year. … Female undergraduates significantly overestimated their fertility prospects at all ages. … The biological reality that female fertility peaks in the teens and early 20s can be difficult for many American women to swallow, as they delay childbirth further every year. … The older you get, the more difficult it is to get pregnant and the higher the chance of miscarriage, pregnancy problems such as gestational diabetes and hypertension, and chromosomal abnormalities such as Down syndrome. … The risk of autism increases with a mother’s age.

More here.  Also, Andrew Leigh:

We estimate the relationship between maternal age and child … learning outcomes and social outcomes. … Children of older mothers have better outcomes. … When we control for other socioeconomic characteristics, such as family income, parental education and single parenthood, the coefficients on maternal age become small and statistically insignificant.

Today high status women stay long in school, start careers, and take long to match up with a man before having kids.  They are often too late, their kids have more defects, and the interruption hurts their career.  Low status women more often have an accidental early kid out of wedlock.

Imagine a different equilibrium, where females pick a male at 15, then school more slowly to have kids till some standard age (20? 25? 30?), when females return to full-time school and uninterrupted careers.

While it is not entirely clear if this new equilibrium would be better or worse, it certainly has some positive features.  Kids and moms would be healthier, kids more numerous and less accidental, moms more energetic, older folk would enjoy more grand kids etc., and career interruptions wouldn’t make female employees suspect.

Early parenting would have to be paid for by grandparents or via loans (or perhaps income shares), presumably in trade for some loss of autonomy.  While childhood does seem to be lengthening, it is not clear if this autonomy loss could be accepted.

For the male pattern, there are two obvious variations: males switch life-plans along with females, or males stay on the current plan.  Having males also switch would keep mates at similar ages, promote healthier kids and more energetic dads, and reduce opportunities for gender discrimination.

Randomness in kid timing and number would make it a bit harder to estimate student quality based on student performance – could we find ways to correct for this?  And the fact that low status moms now have kids early makes it harder to coordinate a switch to this new equilibrium.  But still, it seems an interesting thing that never was, about which to ask: why not?

From a conversation with Rob Wiblin, Katja Grace.