The one-child policy ran from 1980 to 2015 or 35 years, but it was in addition to a number of other restrictions on minimum ages at marriage and childbearing, two child limits for many couples (rural couples, but only if their first was a girl), minimum time intervals between births, heavy surveillance, and stiff fines for non-compliance.
35 years is basically 2 generations - if you figure 20 is an average generation. So if you 1/2 your population twice - what did they think would happen?
Add on top of this that when a nation increases prosperity - which opening trade to the west did from 1990-now - almost without fail the population will self-regulate birth rates and more people will forgo having any children at all. So it’s not suprising that their forecasts were dramatically off.
Regarding the one child policy in China, they have a 500 year plan. I asked someone who seemed impressed with CCP plans how that shortage of women was working out with their 500 year plan? No answer.
CCP is godless. They think they are their own gods. Whatever they do is bound to fail but the havoc and destruction in the path is devastating. It may appear they are wildly successful for a time. Meanwhile Christ reigns and the true church grows under persecution. We don’t desire that type of pain but God always works His plan His way. May the CCP fail hugely, more hugely than ever before. It will be beautiful.
How many of the girl babies in China are put up for adoption? It seems like almost every adopted Chinese baby that I know of was a girl. If large numbers of Chinese girl babies end up being adopted by western families(or sold into sex slavery), then where will Chinese men find wives? Will they have to come here to find a wife and try to convince her to give up her Western standard of living to live in a Chinese urban hell?