Or perhaps tax those with children, since they draw more public services.
Having children is (most of the time) a choice. If you don't have the financial resources to support offspring, the don't have them.
Note: I have (and chose to have) two daughters. My financial situation was one of the inputs into the decision.
"If you don't have the financial resources to support offspring, the don't have them."
This is exactly the problem. People are choosing, quite wisely, to not have kids, so our birth rates are sub-replacement. That's bad, so we need to incentivize people to have more of them. Raising children is a pretty classic externality: benefits accrue to society because we all benefit from continued human existence, but the costs are borne by individual parents.
