This comes up in every discussion about demographics. But counterintuitively, there are no examples of financial incentives actually fixing this problem.

For example, in 2022 Hungary was spending 6.2% of GDP on such incentives[1], but this only managed to bring total fertility rate up to about 1.6 [2].

It is the same everywhere else. The real reason fertility has declined since the sixties is because people have access to effective birth control. Nobody wants to be a baby factory.

[1] https://abouthungary.hu/news-in-brief/hungary-to-spend-6-2-o...

[2] https://www.macrotrends.net/global-metrics/countries/hun/hun...