Why don't black and white Americans live together?
bbc.co.uk
bbc.co.uk
While I haven't lived in US, it seems to me segregation can persist in an unequal society even if racism is marginal: it's enough that buyers of all races observe that higher blackness is correlated with poverty. If that's the case, buyers will rationally flee black areas for the sake of property value. Black affluent buyers will flee to white areas for the same reasons, but if they are a minority they can't balance out. So depending on the correlation of home ownership with wealth (strong in the US), you get a vicious circle where black areas get blacker and their initial majority black residents become trapped there due to declining property values, with the banking and commercial sector entrenching the segregation due to risk aversion.
So once initiated, ethnic polarization is self sustaining even if the initial instigators (racism) become largely irrelevant. Poverty itself becomes the engine of segregation, so the only way to break the cycle is to promote equality.
...so they live together, but just in the South?
This piece had a lot to say about historical prejudice, but doesn't adequately explain why segregation persists. A single anecdote and a throw-away stat about profiling prospective home buyers don't explain things well at all.
You are right that this about far more than realtors steering people one place or another.
But even with free choice, it is worth considering the effects of Schelling's segregation model. Across a large population small preferences go a long way.
https://en.wikipedia.org/wiki/Thomas_Schelling
http://www2.econ.iastate.edu/tesfatsi/demos/schelling/schell...
One only needs to go to NYC's Upper East Side to see this in action. Right above the UES (Yorkville, specifically) is Spanish Harlem.
Before 96th Street? Multi-million dollar penthouses and rentals abound that will impress your friends and family guaranteed. "Gourmet organic" bodegas. Expensive-looking restaurants. Upper-middle-class creature comforts all around.
After 96th Street? Projects. Junk-food bodegas. Domestic abuse shelters. Police cameras. Unmistakeable poverty oozing through the sewers. It's frustrating to watch.
(This contrast is even more stark in much of America. My girlfriend and I went to Memphis during a road trip last year. She went to college there and wanted to show me how quickly Memphis goes from "filthy rich asshole" to "filthy shithole".
There was an approximate 2 block radius of really expensive-looking homes and tree-lined streets that bordered the college. Outside of it? Endless projects.)
The reality is that we live in a racist world, which continues to perpetuate because blacks / Browns and whites are divided, for the most part, across economic lines that will take a long time to be erased, and those economic lines create cultural lines that are harder to bridge.
...or, you know, half the white people. Or a mix of both, and maybe throw in other groups besides black and white.
I'm gonna go for "because the US is still a massively racist country."
A) A rowhome in a squalid neighborhood beset with heroin dealing, unsupervised youth, poor upkeep, and median household income of 10K, a main street of furniture rental shops, cellphone stores and liquor stores that sell mostly "40's".
or
B) A gorgeous house in a neighborhood of other professionals with meticulously maintained and upgraded houses, a mainstreet with a wine bar and coffee house that makes cappuccino's with the fancy swirly foam.
Whether you're black or white, you WILL choose B if you can at all afford it. The sad truth is there aren't enough African americans who can choose B enough to change the optics of this situation.
The pattern persists partly because large cities in the united states consist of the poor or the wealthy with very little inbetween. Middle income folks go to the exburbs because they can't afford the nice parts of the cities and can't afford private school for their kids (sending your kids to public schools in the cities is completely out of the question for any family that values education).