In rich countries, people are expensive.
Even taxi driver in Singapore earns $6k per month.
Now, the "market" tend to correct it self.
If something is expensive, and it's marginal productivity is low, then the "market" would produce less of that thing.
The market produces far more computer than abacus for obvious reason. Once the market produces more and more computer abacus become obsolete and too expensive.
The same way with humans. Humans are getting more and more expensive. So the market produce less of them.
And that's why rich countries produce less and less of them.
Now, I have many doubt about this theory. After all, the number of children you have is not up to the market fully.
It depends on how well you can attract mates to knock up. Yes. That would be market mechanism.
However, there are many government rules that sort make this not market mechanism. Polygamy tend to be illegal. Government tend to subsidize children of the poor with public schools and welfare. Minimum wage means poor people's salary are set by government. Child support laws are set proportional to man's wealth.
But still, market "distortion" may not be that "big". The market may still handle it.
And overall, things still follow market mechanism. The market, decides that we have too many humans. The market stop producing it.
Poor men, for example, can't get a girlfriend. Or poor people think that cost of raising children is too high they decided not to produce children and so on. Those seem like the way the market handles things.
Am I right? Wrong? Anyone study this?