You can also take it as a "the disease is its own cure" situation:
Overpopulation => Ageism => Overworked people => Less children => Less overpopulation
That "one child policy" was the solution. People should get it in their damn heads that they don't really want more economic growth for their country at all costs, as this will decrease their quality of life by getting them overworked to death.
It's 2018... nobody should work more than 4-6 hrs a day, that the fucking reason we invented all this technology and economic machinery!
This reasoning only holds for densely populated and preferably small countries. As soon as a country gets larger and less densely populated cost of infrastructure per capita rises very quickly.
So? Encourage regional independence (to have lots of small countries), and discourage "middle of nowhere" places by not paying from gov money the maintenance and construction of its infrastructure.
Mega-infrastructure monstruosities like highways from Canada to Mexico, or roads and trains from Siberia to Europe, or country wide highways in China are a total waste of resources.
With >50% of work becoming "remote friendly", we'd care less about transport costs going up, and local production could also increase even in less competitive areas.
We keep optimizing for "global productivity" or "global growth" etc. while none of it makes us as individuals happier! Humans are LOCAL in their nature, globalizing stuff beyond a certain point massively decreases quality of life everywhere except a few "hub places".
Overpopulation => Ageism => Overworked people => Less children => Less overpopulation
That "one child policy" was the solution. People should get it in their damn heads that they don't really want more economic growth for their country at all costs, as this will decrease their quality of life by getting them overworked to death.
It's 2018... nobody should work more than 4-6 hrs a day, that the fucking reason we invented all this technology and economic machinery!