What was the previous generation's child mortality rate? From what I read, that seems to be the dominant factor for the number of children you're expected to get, not so much what religion one has.

Probably contraception availability also plays a role there, but I'd be surprised if the two don't go hand in hand: if you have money to spend on healthcare then you'll also have the money for cheap contraceptives.

Edit: another comment (https://news.ycombinator.com/item?id=37720354) linked to a video by the author of the book that I read the above claim in: https://youtu.be/2LyzBoHo5EI?t=962 (the conclusion is what I linked, about 1 minute of watch time)

After WW2? Mortality rates were pretty good. None of my dad’s siblings died in childhood. In Latin America, child mortality isn’t bad either. Catholics (at least back then, and many today outside of the USA, especially in the Philippines) do not believe in contraception.

At population level age of the woman at household formation predicts number of children. It's simple biology.

>Probably contraception availability also plays a role there, but I'd be surprised if the two don't go hand in hand: if you have money to spend on healthcare then you'll also have the money for cheap contraceptives.

Contraception is forbidden by the Catholic Church.

Yeah and we see what effect that is having in the christian 'western' countries

Practicing Catholics are one of the few growing demographics.

It applies to the poorer countries, but less and less so. The more developed countries in Latin America have a birth rate that is similar or in some cases lower than the USA (Uruguay) and are definitely more secular in their culture.