The article seems to suggest that latent racism from the banks, real estate agents and white buyers remains the main engine for segregation even today. While I

The article seems to suggest that latent racism from the banks, real estate agents and white buyers remains the main engine for segregation even today. 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.