> I don't think that would shatter the incentive structure

The best available evidence is that fertility rates are highly sensitive to external incentives. For example Russia managed to raise its fertility rate from the lowest in Europe to one of the highest in just a decade. They did that through a combination of cash incentives, extended maternity leave, and various social status and privileges for mothers.

Yes, but it's it good that they did so? Don't they have enough problems with the populace at large of current size? Such as lack of jobs - having more children than replacement exacerbates it.

The only way it is beneficial is because some jokers decided that running country on ever increasing debt (esp. retirement) is acceptable, and another decided that growth rates have to be high.

uhhh, we already have a shattered incentive structure and are not reproducing enough humans to support the next generation. US fertility is below replacement, as is pretty much every other developed or middle income country. Its likely that we will see peak world population in our lifetime.

Luckily the US population can grow other ways too! And the global population is increasing. And “seeing peak world population in our lifetime” doesn’t sound too scary. Shortage of humans due to humans choosing not to reproduce because they don’t want their non-parent coworkers to be frustrated is one of the smallest existential threats I can imagine.

Among most groups in America, the fertility rate is well below replacement -- same ballpark as Japan, IIRC. The only reason our population grows is immigration: immigrants themselves, and they have more kids than native-born Americans.

So the biological urge apparently isn't doing the trick.

I’m not convinced that the fertility rate in any one country is particularly troublesome, especially when global population is increasing, that country is populous and wealthy, and that country seems to have little trouble growing its population in ways other than local reproduction. This doesn’t seem a problem at all, assuming we’re not talking about other concerns like maintaining certain demographics in the USA (a concern which I absolutely do not share).

That only works if we assume that there will always be rich countries that don't have enough kids, and poor countries that have "too many" kids and send some to the rich countries.

While that may end up being the case for centuries to come, I don't think it's a great outcome for humanity as a whole to require vast wealth inequality between nations in order to keep humanity from dying out.

You're underestimating how well birth rates react to having actual free time and space to live in.

I raise you Israel as an example of not a poor country with big increase in birth rates.