It is one of the most common arguments used to justify federal inaction in pushing communities that get government housing dollars to become more racially diverse: Class, not race, determines where people live, the argument goes. African Americans and Latinos are poorer than white Americans, and therefore, cannot afford to live in whiter, wealthier areas.

ProPublica evaluated race and income data for Westchester County – the affluent New York City suburb under a federal desegregation order – to determine whether income alone accounts for the high degree of racial segregation experienced by African Americans there.

In one half of the split map, we show the current distribution of African Americans in Westchester. In the other, we show the expected distribution of African Americans if black households lived in areas with white households of the same income.

The differences are striking. If income were the only determinant, and black residents settled wherever they could afford, Westchester would look dramatically different. Areas such as Yonkers and Mount Vernon where African Americans are heavily concentrated would be a lot less black. More affluent places such as Eastchester, Scarsdale and Bronxville, now overwhelmingly white, would be significantly more diverse -- even if the county did not build a single unit of affordable housing.

Some of Westchester’s living patterns likely reflect preferences among African Americans to live among other African Americans, but scholars warn against overestimating the effect of choice.

“When African Americans and Latinos end up living in segregated communities, those communities are poorer, and have worse schools and higher crime rates. They are really paying a price for that segregation,” said John Logan, a Brown University sociologist and segregation expert. Black segregation isn’t “because they prefer to live with their own people, just as whites do. I think it is because they have limited choice in the housing market.”