Can I add to this list, for reasons of completeness, the concept of 
children as durable
goods, as coined by Gary Becker?

In the US the costs of children are mainly perceived as private costs,
whereas in most European welfare states a considerable part of the 
costs of children are financed
through taxation or by additional flexibility and programs by employers.

I miss in this discussion the opportunity costs of (mostly) mothers, 
which can add up to 500.000 over a life time.
Was it Schumpeter who said that when all individuals would really act 
on the basis of self-interest only, children would not be born?

Edith Kuiper