The Chinese government seems to be convinced that China's diminishing
population is
a bad thing.
The only putative reason cited in this article is that taking care of
old people will be a lot of work. Yes, it will, but younger adults
could take care of more old people if they are taking care of fewer
children. Anyway, In 30 years, robots will do a lot of that work. In
addition, a larger fraction of people over 60 will be able to work.
The natalists do not respond to these points.
I suspect that an additional unstated reason is that a bigger
population could make China more powerful internationally. That is
not a moral justification to increase any country's population.
Some claim that the one-child policy had no significant effect after
1981. Others claim that continuing it reduced the birth rate even
more. Those claims cannot both be true.
Now that Chinese are becoming somewhat prosperous — which they
deserve, as everyone does — China is starting to drive worldwide
production of some goods, much as the US and Europe do. That is part
of why we are exhausting our planet. We need to reduce the Earth's
human population to achieve sustainability.
So we need to reject the idea that the population must not fall.