[Trickyguy]

If you want to fix most of the problem, cut taxes by 90% and welfare by 100$. Then more of the better and less of the worst will be born.

[m18436572]

I have a sneaking suspicion that you are correct. This seems to be a class problem.
Lower classes have no reason not to breed.
As your wealth increases, and your expectations of how your kids should be raised becomes more of a concern, you see more reasons to postpone, or not have as many, or completely forego having, children. Parents raising kids to the same or better standard of living they enjoyed as kids today seems almost impossible. Just a gut feeling.