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 mean that I know of first hand, just the US and Japan. "Possible" being a low bar that just means that I've seen it at least once.

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.

It's a simple catch-22

- women don't want to leave the workforce because one salary cannot support a family

- yet women remaining in the workforce, since single-salary is infeasible, thusly doubling supply of workers, lowering salaries, which itself makes it infeasible to single-income a family

Not to pick on women, as a feminist if you ask me, all modern men should have to be houseboys to serve their feminine masters. It does suck but it is necessary to benefit the modern women who did not suffer, in so by causing modern men to suffer -- to make amends for the suffering of all women in the perpetuity of history at the hands of all historical men, neither of which are alive today.