This is very true. It's proven itself over and over in history. The more stable, healthy, and developed a country is the less children it has. Europe and East Asian countries are having this problem right now as both have negative population growth. In fact this might be the solution to over population. If I knew I'd live to 150 I'd probably wait till I'm 75 to reproduce and replace myself with children.

Well, you've outed "Chris" as the male form of the name "Chris" as there are certain female reproductive system issues where once you're outta eggs thats all folks. Dudes are fertile to a ripe old age. So at 75 you need a wife 1/3 your age.

The cultural issues could be pretty huge if women are only fertile for a small fraction of their life and dudes are fertile for X times as long as women. Or maybe it becomes a cultural "job" of young people to churn out kids as fast as possible for old people to raise them, which we seem to already be implementing in certain socioeconomic classes.

Good point. But I'm sure that's a problem that will be solved by that time.

Not sure if this is 100% true but "It had been widely accepted that a woman was born with a limited number of eggs [...] But, in 2012 this dogma was challenged in a paper that found proliferative germ cells that sustain oocyte and follicle production in the postnatal mammalian ovary. This means that women do not have a limited number of eggs."

OK interesting, but the larger scale problem exists now where most 75 year old women are infertile. That could be "fixed" by yet another medical breakthru.

that's an ongoing debate but does not change the fact that women hit menopause in their mid 40's right now.

disclaimer: my wife and I have spent about $100K over the past 6 years trying to get pregnant, including several IVFs and a failed donor cycle (that's where you write a check for $30000 and flush it down the toilet).