The other day, John Derbyshire, a writer who is somewhat prominent in conservative circles, was disinvited from his regular gig at the National Review for a piece elsewhere on the inflamatory things he's warned his children about with regard to African-Americans (though outside of politics, his book on the Riemann Hypothesis is supposed to be quite good). Outside of a handful of political blogs, it's not particularly newsworthy, but one thing he told Gawker struck me.

The natural preference most people have for some races—usually their own—over others means that multiracial societies are plagued with stresses that you don't see in monoracial societies. The tendency in modern times is to separation. Look at residential and educational patterns in the U.S.A. I discuss these issues at length in my book We Are Doomed.

It struck me because I was reading up on the effect of segregation on the housing market in Chicago and elsewhere, inspired to do so by a WBEZ story about how the city is having trouble selling houses, refurbished at considerable federal-government expense, even well below their ostensible costs. And I came across this 2008 study of segregation and housing (emphasis mine):

45 percent of whites have searched only in communities where whites are in the majority (that is, constitute more than 50 percent of the population); and just 4 percent have searched where any other group is in the majority. Second, approximately one in four whites have looked in both neighborhoods where they are the majority and where they are the minority. (The remaining one-fourth of white respondents have either not searched for housing in the last 10 years, or have searched in communities that were not identified on our map, whose racial composition we do not know.)

For blacks and Latinos in Cook County, house hunting is a very different experience. Just 8 percent of blacks have looked only in majority (more than 50 percent) black communities. Moreover, one in five blacks has searched exclusively in communities where blacks are in the minority. Mostly, then, blacks have searched in both kinds of communities—those where they are in the majority and those where they are in the minority. Indeed, 81 percent of blacks included in their search locations a community where they are in the minority. These results severely challenge the view that blacks prefer to self-segregate in majority-black neighborhoods.

Latinos show a similar pattern. Fully 35 percent of Latinos searched only in communities where another group was in the majority. An additional 37 percent of Latinos searched in both communities where they were in the majority and ones in which they were in the minority.

If my count is right, 31 community areas in Chicago are majority non-Hispanic black out of 77. If blacks are much more willing to move into neighborhoods where they are a minority than whites are, that's going to have a substantial effect on the market, driving up prices in desirable (or even merely marginal) neighborhoods and reducing mobility. Or worse, as Megan Cottrell wrote in 2010:

Researchers at Princeton say that without segregation, the expansion of these subprime loans, and the subsequent economic crash, couldn't have happened. Mortgage brokers needed swaths of communities where people met the following criteria: 1) they didn't already have a home loan, 2) they were used to predatory lending practices, and 3) there weren't other financial institutions around to clue buyers into the fact that these subprime loans weren't a good deal.

It's not a simple matter of black people being way more egalitarian than white people. Everyone wants to live in a safe environment with good housing stock and good civic resources, which is often not the case in black-majority neighborhoods in Chicago, as Robert Sampson writes in his paper "Social Anatomy of Racial and Ethnic Disparities in Violence":

Racial/ethnic differences in neighborhood characteristics are pronounced. For example, a typical Black in Chicago lives in a neighborhood that is 78% Black, whereas Whites and Mexican Americans live in neighborhoods that are more mixed but that are still predominantly (over 85%) non-Black. Blacks are also more likely than Whites or Mexican Americans to live in neighborhoods characterized by concentrated disadvantage, high legal/ moral cynicism, and low collective efficacy.

Advantage and collective efficacy can stabilize a neighborhood, as it did for Chatham, long an enclave of the black middle-class on the South Side. Sampson, in his recent book Great American City, found that the neighborhood has the second highest collective efficacy among predominantly black neigborhoods (behind Avalon Park, nicknamed Pill Hill for its concentration of medical professionals). But it borders on some of the city's poorest neighborhoods—such as Wentworth Gardens, where the men who killed police officer and Chatham resident Thomas Wortham IV lived. Over the past two decades, Chatham has lost 15 percent of its residents while seeing greater poverty and unemployment, which is one reason Sampson calls it out in his book as an area of concern. If people can, they move to places like Chatham over places like Englewood and West Englewood (which each lost nearly twice as many people in half the time). If places like Chatham become too unsafe and isolated, they move out of the city:

In addition to migrating down South, black Chicagoans are also heading for the suburbs, including Cook County's Dolton, Ill. Over the last decade, blacks who achieved a certain amount of success before the economic decline began moving to the suburbs from the city in search of safer communities and better housing. They also spread to University Park and Orland Park, both in Will County, with Orland Park straddling Cook County. Will County, with a population of 677,560, saw its overall population increase 34.9 percent, according to the Census Bureau.

In 2000, Orland Park was 0.7 percent black and 3.7 percent Latino; in 2010, it was 1.7 percent black and 6.2 percent Latino. Will County's percentage of black residents didn't change much from 2000-2010, but that was while the country grew by 35 precent. The percentage of Latino residents almost doubled over that period.

Derbyshire is apparently of the opinion that the housing market is frictionless, and housing and education patterns are exclusively or mostly a matter of choice. But there's plenty of evidence to indicate that it's not:

The study was conducted between 2003 and mid-2005 in 12 metropolitan areas using teams of "paired testers"–individuals or couples posing as home seekers to compare how randomly selected agents treat African-Americans, Latinos and whites.

The 73 real estate firms tested were in the metropolitan areas of Chicago; Washington, D.C.; New York; Philadelphia; San Antonio; Detroit; Atlanta; Pittsburgh; Birmingham, Ala.; Dayton, Ohio; Mobile, Ala.; and Austin.

[snip]

The African-American and Latino testers were assigned financial qualifications that were slightly superior to those of white testers. They had higher incomes, could make larger down payments, had longer employment tenures and could afford more expensive houses than the white testers.

The results were sobering: White shoppers routinely were steered away from houses in predominantly minority or racially mixed neighborhoods, even when they expressed interest in seeing houses there. African-Americans and Latinos routinely were steered to minority neighborhoods and away from more affluent, white neighborhoods, even when they wanted to see houses there.

As the Chicago Reporter detailed in a 2007 story that led to a $335 million settlement, the same patterns persist in lending.

Besides: it's the housing market. If we've learned anything last decade, it seems like it would be that when someone tells you a market is frictionless and ahistorical, check your wallet.

Photograph: frozenchipmunk (CC by 2.0)