To live a fulfilling life without the constant fear of not being able to adequately provide for yourself or your offspring?
>And who pays?
Since it'd be us, collectively, as a society who would benefit it'd make sense for us, collectively, as a society to pay.
And this comes, for free, with no obligations? What is the standard for a "fulfilling life"? One child? A hundred? If I think my life will be fulfilled by skydiving, or playing XBox, or hookers and blow - should the state pay for those as well?
> it'd be us, collectively, as a society who would benefit
What you are describing is a market, but with no feedback or control; When someone ends up a burden on society due to a poor upbringing, does "society" get a refund?
If we are paying for people to bring up children, it would make more sense if the we initiated it; rather than people self-select for parenthood and get child welfare as an individual right.