[dpflan]

“””

If the recent decline in annual birth rates simply reflects women pushing off having children from their 20s to their 30s, then annual birth rates will eventually rebound and the total number of children the average U.S. woman has over her lifetime will not change. But the decline in annual birth rates since 2007 is consistent with more recent cohorts of women having fewer births. Those cohorts have not completed their childbearing years yet, but the number of births they would have to have at older ages to catch up to the lifetime childbearing rates of earlier cohorts is so large that it seems unlikely they will do so. If the decline in births reflects a (semi)permanent shift in priorities, as opposed to transitory economic or policy factors, the U.S. is likely to see a sustained decline in birth rates and a general decline in fertility for the foreseeable future. This has consequences for projected U.S. economic growth and productivity, as well as the fiscal sustainability of current social insurance programs. “””

Will have to check back on this in a few years.

[wunderland]

If women push back childbirth to their 30s, fewer births with happen overall because quite simply fewer women will be able to conceive.

[furyg3]

> in the United States during 2018-2020 (average), the highest fertility rates per 1,000 women were to women ages 20-29 (80.1), followed by women ages 30-39 (75.3) [...]

Source: https://www.google.com/search?client=safari&rls=en&q=birth+r...

[derbOac]

"...ages 40 and older (12.8)."

Part of the issue is the infertility cliff happens in the late 30s to mid 40s, so those age categories are a little wonky in terms of capturing the phenomenon.

Having bumped up against this myself, the problem in the US isn't that women are more often waiting until they are 32 to have kids, it's that they are waiting until they are 39.

The figure here illustrates it well:

https://www.census.gov/library/stories/2022/04/fertility-rat...

There seems to be a much bigger decline in births among younger than there is an increase in older, but if those women are delaying rather than abstaining completely, they'll run into infertility issues later if they wait late enough. There will be a certain number who intend to have more kids than they actually do.

I don't think this is all of it, as it doesn't address why women are increasingly forgoing children in prime fertility years. I also in general think it's part of a set of demographic trends that point to societal problems (stalling or declining life expectancy for one).

[EForEndeavour]

Note that these age-specific fertility rates measure the number of births per 1,000 women. This does not directly measure how easy it is for a woman in that age group to conceive (what OP referenced), because fertility rate is confounded by the degree to which women (1) actively try to conceive (versus avoid conception), and (2) decide to carry pregnancies to term.

[surgical_fire]

It reduces the amount of young people however no?

If people have children in their early 20's, is conceivable that by the time of their deaths at least 3 generations of their descendants would be alive.

If they instead choose to have descendants in their late thirties, only their children would exist, and perhaps their grandchildren would be in their early infancy.

I know many people that don't even want to have children, and even among the ones that do want, most push it to their late thirties, and stop at 1.

I don't really think it's a problem. It's just how life nowadays is set up, for economic, professional, sociological, and cultural reasons.