Earlier quoted context omitted.
> That's completely out of the realm of reality for many young people now and the plummeting birth rates show it. I'm skeptical of this explanation for falling birthrates just because birthrates are falling across the world and there seems to be no correlation between fertility and financial security. America has low birthrates. Scandinavia (usually considered to have generous welfare states) has low birthrates. Hung…
In which of those countries is it possible for a man to work an ordinary job, buy a house, settle down with a wife and support two or three children?
I don't think data with all of those factors (household income, number of earners per household, gender of the earners, home ownership, and number of children) exists for any country. Do you have data like that for 1960s America or is your argument based on extrapolations from watching Leave it to Beaver?
But if we abstract your hypothesis slightly to: fertility is lower now than in 1960 because people are less financially secure now than they were in 1960, I don't think the data we have supports this.