Granted that the average is as you say. But averages conceal the truth that the racial composition of those US districts that I have seen personally is genera

Granted that the average is as you say. But averages conceal the truth that the racial composition of those US districts that I have seen personally is generally not average, they tend to be overwhelmingly white or overwhelmingly black (mostly the Raleigh-Durham Triangle). In Norway we don't have many areas where that happens.