Birth rate has generally been inversely correlated to income. AFAIK this is true in almost every country. The plot of Idiocracy was derived from this phenomenon

Birth rate has generally been inversely correlated to income. AFAIK this is true in almost every country. The plot of Idiocracy was derived from this phenomenon. Humans are complicated and there are probably multiple reasons for this. But the most convincing one that I've heard is tied to education. Higher income generally means better education. And the better educated are more likely to use birth control. https://wol.iza.org/uploads/articles/228/pdfs/female-education-and-its-impact-on-fertility.pdf https://wol.iza.org/uploads/articles/228/pdfs/female-educati... I mentioned before that birth rate and income are generally inversely correlated. But that isn't completely true. The relationship is more of a j-curve. That is, past a certain income (think top 5% or more), the fertility rate begins to tick up. https://en.wikipedia.org/wiki/Income_and_fertility#:~:text=There%20is%20generally%20an%20inverse,born%20in%20any%20developed%20country https://en.wikipedia.org/wiki/Income_and_fertility#:~:text=T.... So, the breakdown is basically this: - The lowest-income/least-educated have the most children by far. - As you climb up the middle income/college-educated ladder, fertility drops almost linearly. - The wealthiest have more kids than the upper middle income, but still a lot less than low income.