Contrary to what most economists and analysts tell us, a large population, or even a growing population, might be more harmful than beneficial in the new age of AI and robots. Indeed, if you're a military analyst you might come to regard a huge population mass of like 1.4 billion to be a burden rather than a strategic advantage. What a huge target! How do you feed it, how do you control it, what happens when he gets out of control?
If we want to talk about national wealth, much depends on how we define it but if we define it as the mass of goods divided by the number of supplicants for those goods we begin to ask, if our GNP is produced by artificial intelligence and robots, do we need more than a billion people to increase production? If we are dividing the sum of production by the population, would not a more manageable population make us richer rather than poorer?
If we are entering a technological age in which wealth at the level of conception is done by a very few brilliant human minds while the bulk of production is done by smart machines, how do we distribute the wealth? If we don't distribute the wealth, do we risk revolution? If we do distribute the wealth will we certainly kill off incentive?
It seems to me these questions become all the more intractable the more disparity between the elite and the consuming class is increased by virtue of size of population.
Most of the arguments in favor of large population, or more intelligently, of growing population, center on the need to create markets for consumption. In an age in which 3D printing is making us rethink the entire concept of economies of scale, should we not also rethink this maxim?
Finally, in Japan the age of robots may well make the geisha class redundant. Why not in China where there exists a disparity of number between the sexes?
Okay, perhaps that is taking this robot business too far.
It is easy to dislike the Left and their Global Warming hoax, and their hysteria over food production and population control. The Left clearly seems to seek a world with a substantially lower population. They would (I think) be comfortable eliminating more than half the population so that they could live comfortably with lots of stuff. The Agenda 21 concept seems to center around this sort of thinking.
Now, I find that despicable and short-sighted. The Left seems confident that people like me could be eliminated and people like them could survive and live lives of splendor.
But if we take a step back from Globalism, population control of useless eaters, abortion, euthanasia and other assorted Leftist monstrosities, I think the point you raise is actually quite cogent.
We are heading for a post-scarcity world in which automation shoulders much of the weight formerly carried by human labor. What then?
We really don't need big populations. And big populations with nothing required of them are likely to be disruptive (the devil makes work for idle hands).
I would oppose tyrannical population control, of course. But society might want to start thinking of gentle, non-coercive ways to get our population down below 100 million or so. I don't imagine it would be easy but I see no reason not to.
One thing you left out:
Without a large population, you will not get a great number of geniuses on the left side of the Bell Curve.
Well... unless you genetically engineer them.