Why not a childfree tax instead? It's not going to be popular, but for societies with low birth rates - contribute to the next generation either via human bodies or via cash. But I doubt society's ability to put this tax towards the next generation.

I believe childfree tax is an really bad idea as there are so many examples shows how cruel parents can become when they have no intention of taking responsibility for their children. Enacting strict laws against abuse can prevent some extreme cases, but do we really want child to grow up in an hostile family?

Sure, that works, but I think the incentives work out better for the children with a child tax than a childfree tax. With a child tax, there is an additional economic incentive to invest in the child (food, education, wellbeing, housing when they're starting their career), while the incentive ends at birth for a childfree tax.

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