I think the fictional evidence misses a key factor in raising kids. At least for some people the continuation of a line, that line either being blood or values. I think most soon to be parents don't look forward to the nasty sleepless evenings with newborns or such. But give the availability of abortion, we still do not see L'Dolce Vita culling all humans from the reproducing herds.
People do enjoy long term endeavors. I find the idea that my line will stretch far into the future to be a very good driver in my quest for higher education and wealth attainmen...
I love this blog.