The Rich Have More Kids

Bryan Caplan finds that while more education (and being born later) predicts fewer kids, controlling for those factors (and age), more income predicts more kids. I don’t recall doing so, but Bryan says I predicted this result with some confidence years ago, but that he was skeptical at the time. Here are Bryan’s results predicting number of kids for men:

and for women:

Note the year effect is about the same for men and women, but the education effect is twice as big for women, while the income effect is twice as big for men. (All effects are highly significant.) Bryan concludes:

If you’re prone to futurist speculation, trying re-imagining Idiocracy.  The twist: in the real world, the most fertile people aren’t those with low IQ; they’re people who counter-stereotypically combine low education with high income.  Plumbers shall inherit the earth!

Bryan would be right if humans continued to dominate the Earth via ordinary reproduction. However, if (robot) emulations instead dominate, the question is whether the sorts of attitudes that tend to make people want to make more kids also tend to make them want to make more emulation copies. I predict surveys would find a positive correlation in these attitudes. At least I predict this conditional on respondents being induced to accept the emulation scenario as real, which is the frame of mind people would be in if emulations became feasible. Hence I predict while emulations would select heavily from our most productive folks, who tend to be well educated, emulations will tend to select from the richer but less educated part of this population. Really good plumber emulations shall inherit the Earth.