Why not pay women a competitive (not $10/hr) salary for raising a child, collected from taxes from people who don't have children under 18? To make building a family more profitable than working a job. It seems that politicians (calling for ban of abortions) want to have a cake and not pay for it.
So you basically want to add another tax on young single/unmarried people?
What if you are infertile? Is the government/state going to pay for all the procedures related to adoption/ fertility treatments?
What about gay people? Would they be forced to adopt kids or use surrogates to have children so that they stop paying this tax?
At what age should men stop paying this tax? After all, a man in his 60s and even later can still in theory father a child with a younger woman, so there is really no cut off date for men in this case?
Finally why not pay men as well if they are the ones doing most of the child raising? This would apply in cases where the mother died or left. Would that be acceptable?
I am sorry to say but your proposal is not very well thought out and on top of that your forget that people in relationships without children are already paying more than there fair share of taxes.
A single child raised to adulthood in the United States is worth over $10 million to the economy. Consider that in the calculation of what a fair share of investment bringing that into the economy is.
For example, a Russian millionaire, Pavel Durov has 5 children, although it seems that they are raised by his ex-girlfriends. Once there is enough money, problem is solved.