It's the opposite with humans. 3rd world/developing countries have extremely high birth rates. The best mechanism for "population control" in people is to improve a population's standard of living.

I don't think that it's a matter of worldwide standard of living. I wonder if developing nations have an easier time with a young person reaching a comparable standard of living with their parents, and the developed ones have a much larger discrepancy. In a developing nation success might be somewhere to live, and a job. Before someone from north america is "doing well" you need a partner, a 5 bedroom house, two cars, two jobs, and a university education. We can't meet our "needs" until much later in our life.

>Before someone from north america is "doing well" you need a partner, a 5 bedroom house, two cars, two jobs, and a university education. We can't meet our "needs" until much later in our life.

If it's what your priorities are you can have a home, cars, max out your 401k and be paying back student loans on a single entry level tech salary.

This requires that you put up with a long commute, beater cars, an old house and DIYing a good chunk of skilled trade work that you could hire someone for. You'll be bringing your own lunch to work, drinking beer from a can and not building much cash savings at that stage. Nevertheless it's sustainable on a single entry level tech income in a major urban area and living a couple hours away.

I think that increased spending on luxury things has by implication de-prioritized the "life milestone" things.

Generations ago people bought a house and started a family first. Now people accumulate wealth first and settle down later (which is probably a reflection on the fact that the lifestyle needed to accumulate wealth is not very compatible with settling down).

That's exactly what I'm saying - the goalpost for what "doing well" is has moved, we now expect more of ourselves because of the visible relative affluence of our immediately previous generations. We don't see how the baby boomers started, but we see how they are ending, and that's set the goal for our own success.

More precisely, it seems to be to improve the strength of social safety nets (that correlates with standard of living, but also explains places in the developed world where the average standard of living is high by developed world standards but the birthrate is also high for the developed world.)

The reason for this may be that, in the absence of public social safety net, family (and particularly close family) serve as a safety net, and particularly children, once they are able to be productive, can be a kind of safety net against infirmity for their parents.

3rd world has high birth rates because:

- lack of birth control and related education - desire for “free” manual labor to work stuff such as farm fields - desire to ensure continuity of one’s family tree (i.e. high mortality rates for infants and children due dangerous conditions and/or lack of healthcare)

>3rd world/developing countries have extremely high birth rates

Their birth rates are also declining and doing it with increasing speed.

> most species reproduce when resources are abundant

I dunno, fungi usually don't produce mushrooms until right before their host is about to die or their substrate is about to be depleted. Reproducing takes a lot of energy, so individuals usually wait until they have no other choice.

Humans seem to be the same way. E.g. low-income kids go through puberty sooner, presumably due to having poorer health. And usually if someone starts drinking a lot or otherwise abusing drugs, they get really hot for a year or two before they start looking sickly and terrible.

At the population level species keep reproducing until they use up all the available resources, and then the populations collapse, but on the level of individuals the dynamics seem to work in almost the opposite way.

but the scarcity here is artificial, induced by unfairness in economic opportunity in spite of more than abundant resources economy-wide.

if we had a more fair economic system, more families would feel economically secure enough to have children.

the minimum level of economical security required rises proportionally with wealth and income disparity, because our economic outcomes are inextricably tied to each other through inflation and the like.

That does not correlate well with the facts.