[nabla9]

Increasing education, living standards and changing preferences create forces beyond government control. Just allowing and supporting more children is probably not enough.

>China’s Population on Track to Peak Before 2025 as Births Drop

Almost exactly at the same time as Taiwan's population is expected to peak. South Korean and Japanese populations are already in decline.

[ZeroGravitas]

Some people may have considered limiting children to one per family to be "beyond government control", so there's probably some good sci-fi to be written/lived through on the topic of what a totalitarian government will get up to when it's realised that more children are "needed", but that most parents won't volunteer to provide this service.