[Crawford]

Right, Boston is fairly affluent, and there are no real North Philly or South Side of Chicago-type concentrations, but there's still pretty considerable poverty and racial isolation. Roxbury, Mattapan, and Dorchester aren't great areas and gentrification is pretty limited. Not a SF or DC level of gentrification. Also, Boston, unlike SF and DC has WWC areas in city proper still.

Boston might just be lucky, but I'd guess gun control, immigration, heavy social/education spending help. It's a bit of a third rail discussion, but the black population is heavily foreign-born and immigrant black communities don't have the same frequency of violent criminality. Boston black population is like that of NYC and Miami.