It’s politically incorrect to say this, but many people are having fewer children or not having children at all. The Muslim population in Europe are having more children than native Europeans.
Sad to say that reproductive choice all too often means not having as many children, for lifestyle reasons. If “demography is destiny” the civilized world as we know it is in trouble.
White people (and Japanese people) damned well need to give up the flatscreens and the bass boats and start having children again. It’s that simple.
NB: I am a white person and a father; we hope to have more.