[pjschlic]

Did you have (even a vague) source for this - I'm willing to search for it given even a vague gesture? I think this indeed sounds like it could be strong evidence, so I'd love to see it. Indeed, I would also think that a high skill population living mixed with a low skill population would have a higher birth rate than a high skill population NOT near a low skill population.

[chrchang523]

You can start from https://en.wikipedia.org/wiki/List_of_U.S._states_and_territ... and its list of sources, and drill down from there. Remember to subtract births to recent immigrants from the numerator, and number of recent immigrants from the denominator. It won't take long to verify my claim.