[muyuu]

China has been in (artificially) in demographic decline for a while most of the country remains dirt poor.

There is no such cultural determinism. Many countries won't stop having children as their economy grows, in fact the opposite is happening in many places around the world.

[aksss]

Nobody said anything about "stop having children" (good night!) - back to reality: I think the established pattern for countries joining the developed world is large economic growth/dev, followed by baby boom, followed by declining rates of reproduction until under the replacement value. This happens not only because of changing priorities of a wealthier population and changing behaviors, but also the availability of birth control and lower mortality rates (infant and elderly).

So it's not that birth rates decline "as their economy grows" - the birth rates go up during the growth phase - it's what comes after in an established prosperous society: fertility rates decrease.

It's consistent enough to predict with some certainty. As prosperity has grown worldwide, so global TFR has dropped. This happens one by one with the individual countries following a predictable pattern.

China does have regulatory limits that keep their TFR lower than it otherwise would be, they are still in their (modern) growth cycle. Absent that regulation, with the economic boom they've been seeing in last twenty years you'd expect to see the fertility rate boom accordingly, and while it appears to be growing despite the regulatory constraints, it's still below replacement value. This slow growth in the face of structural prosperity changes is the impact of regulation, not organic. https://www.macrotrends.net/countries/CHN/china/fertility-ra...

[muyuu]

my entire point is that such determinism is illusory and your example wrong in every way

there are direct factors that explain away TFR drops that are not "prosperity" - in fact prosperity alone has historically increased TFR pretty much every time

drastic drops in fertility rates in Europe and North America respond to very specific cultural phenomena that are unlikely to happen in a similar fashion in Africa or the Middle East, more likely to happen in South America and parts of East Asia to some extent, but certainly not across the board

social pseudoscientists can spend as long as they wish looking at past charts, they still won't see causality and there is no better example than fertility predictions to showcase The Poverty of Historicism

[aksss]

I think you're still missing the idea that after the growth phase which triggers a boom in population, that sustained prosperity after the growth spurt is when TFR starts falling off.

Look at any given developed society today (characterized by long-term peaceful stability and general prosperity, development of professional classes, liberalization of gender roles, shifts away from field work) and you'll see TFR falling below replacement levels. This isn't a "western" phenom, you can see it in Korea and Japan as well, for example.

It's simply practical economic decisions by individuals - kids cost a crap ton of attention and money, and when the risks of them dying have decreased (lower mortality due to medical care, less war/violence) and the obligation to reproduce is lowered (changing gender roles, birth control availability, women having options for professional careers), and kids are less useful as labor units, you get fewer of them. Predictably. Across hemispheres.

I suspect your examples are all "developing" countries, not "developed" but you've thus far only referred to nebulous regions and continents. Interested in a specific example of a developed country that has not exhibited this pattern.