There was an article in the Economist way back when the Economist was center-right, that when the percentage of blacks crosses a certain percentage of the population in a town or city, the economy crashes, crime markedly increases etc.
I think the conversation was about the north end of Charleston South Carolina which is towards Summerville which is very nice
Charleston is nearly half black and more black than white
But the historic part is nice
I could be wrong
Reply Could have meant Charlestown Boston