How do you account for the cost of a delivery? Do we just assume a totally fine birthing experience? What if there's complications? The emergency blood transfusion sure isn't free. It's also not predictable individually.

Ooh I know we'll calculate the cost across the mean population. Of course almost everyone has children or was a child, or knows someone who will and is invested in their well-being. And we can't account for when births happen so we need to keep facilities staffed in downturns, and account for future expensive deliveries where neonatal care is needed.

So really, the best strategy would be some scheme where we charge everyone a little - and the more people we add in the pool the smaller it'll get.

If only there were a name for such a system...