This is what you're missing. They are not.
When the Titanic hit the iceberg, you could have gone from 0 people bailing water on the ship with buckets to the whole complement of crew and passengers (if you had enough buckets). You could talk about how there's now thousands of gallons of water being bailed out of the ship per minute. Without the context of the actual cause it would sure sound like a lot of water, like a meaningful attempt. But the Titanic would still sink.
In the last 100 years, we went requiring 1 income to support a household to 2 incomes to support a household. Everyone acted rationally, but its a very large scale prisoner's dilemma. Women wanted economic freedom and the economy was happy for more labor. There was no accounting for the labor women had already been doing. And so dual income households, at every level, pushed up the prices of everything that can't come out of factory in China. Even at the scale of ~300k individual incomes, a second person bringing in 100k-200k makes a noticeable difference, right? So for 99% of the population, dual income for some # of years, just til we buy our first house, just need a new car, well you get used to the standard of living dual income provides... and houses are more expensive now... jobs less secure... and you'd have to see online what you'd be missing out on...
Well, we took the "slack" out of the system and sold it. Without really being aware of its value.
And now governments, like those of Korea and Singapore, are trying to buy it back, but they haven't _really_ grappled with the scale of debt that was incurred, because it wasn't on any balance sheet.
I think this is the key insight, on this specific topic and many others.
The government is not going to give you more money to rent a bigger place or buy a bigger house so then you need to factor in those expenses as well not to mention the partial and sometime total loss of income of 1 adult for the first 2/3 years of the life of the child.
The math just doesnt work.
Starting with the second child. You don’t get anything for the first.
My mom used to say exactly the same, but she still got 3 kids with very little money because her social groups expected her to have children.
Catholic?
I think that in modern societies children are a bad investment, but not only for this reason. If anything, I think that fertility rates were going down even before uncertainty for the future was up. Another commenter talked about urbanisation, and that in an agricultural society children were an investment, while in an urban one a liability. Some efforts focus on reducing the cost of having children, via social benefits etc, but the core reasons behind making having children actually costly is rarely addressed.
I might note the role of 24x7 News and the attention economy in temporal inflation - "We Are Doomed, Because _______" stories are great for audience- and profit-building, but they keep dialing up peoples' expectations of temporal inflation.
And "temporal inflation" is easily dumbed down to "their future looks sh*tty, to them" - which feels like it could get through, to at least a few of those who are skillfully and willfully oblivious to the causes of the problem. Hopefully. Maybe.
Skilled professions were likely to remain useful after the war. AI makes their future value seem uncertain.
The results would also likely be skewed by Germany quasi-forcing people to have children in support of the party.