Earlier quoted context omitted.
Birthrates are problematic as it usually take 20 to 25 years before they pay taxes. And in that time they require a lot of expenses. They talk abiut the squeeze, if Birthrates increase too suddenly - workers would both have to pay for the elderly and the kids.
This is the real demographic death trap, and why Taiwan and South Korea are probably past the point of no return. If one generation has a fertility rate of 1 child per woman, the next must have 4 children per woman to undo the demographic change. The people in the “corrective” generation must support their own two elderly parents plus four of their own children. It becomes practically impossible.
The country and the individual has the same problem. But it also goes a generation further.
There was a link on HN recently which I can’t find. It discussed how we are in an unusual time, where kids can often meet their great grandparents. Previously people died younger, so couldn’t. Now people are having kids at an age where it will be unlikely for them to meet their great grandchildren.