Day care for infants and toddlers.
https://www.reddit.com/r/sanfrancisco/comments/cqegh2/daycar...
https://www.reddit.com/r/sanfrancisco/comments/cqegh2/daycar...
https://www.reddit.com/r/breakingmom/comments/qtk3d8/how_we_...
So the difference is conservatively 2000 extra per month per child.
The point is this scales linearly so two kids is 4000, three is 6000.
The amount of child expenses in Europe goes up hundreds per month. In USA it goes up by thousands a month. That’s an order of magnitude difference.
More kids, the better Europe becomes compared to USA.