Nope, it’s that affluent people and nations usually have smaller family sizes. It’s correlationally, not cause.
Just like ice cream sales correlate to murder rates. As one goes up, so does the other. The third factor in the equation is that summer and heat correlate with both, and is probably the causal factor.
It’s one of those things drilled into me when I was taking my psychology courses in undergrade, and why research and experimentation is necessary, rather than relying on correlation. Otherwise we might as well be sociologists and nobody wants that.
Anyway, the original psychology article was already posted above.
A scenario that occurred to me last night was the Dems win the Presidency and the Senate in 2020, but RBG passes away a week later. Trump and the lame-duck R’s march through another far-right justice who passes on a party-line vote.
He’s already said that he’d appoint a judge all the way up until the last day of Trump’s presidency. He’s said, “Oh, it’s only a problem when the senate is controlled by a different party than the President.”