Three Texas cities top a new undesirable list. San Antonio, Houston, and Dallas-Fort Worth are apparently the nation’s most economically segregated metropolitan areas, according to a new Pew Research Center study. This mean that those cities have a higher share of “lower-income and upper-income households who live mainly among themselves.”

Economic segregation is on the rise throughout the country. “Residential segregation by income has increased during the past three decades across the United States and in 27 of the nation’s 30 largest major metropolitan areas, according to a new analysis of census tract and household income data by the Pew Research Center,” Paul Taylor and Richard Fry, the study’s authors, wrote of their findings.

The Houston Chronicle‘s Mike Tolson looked back at how his city’s growth over the last few decades led to this:

Roll back the clock to 1980 and Greater Houston looks quite a bit different. Some of the tall buildings, meandering toll roads and shiny professional sports venues aren’t there, of course, but of more significance is the absence of many places that Houstonians now call home.

As the metro area’s population doubled over the past three decades, extensive developments and master-planned communities popped up or expanded to serve those with the means to buy spanking new homes on the suburban fringe. As for those of little means – many of them immigrants, legal and otherwise – they increasingly crowded into older, low-income neighborhoods abandoned by residents who lost jobs or found better housing elsewhere.

The result, according to a new study released Wednesday by the Pew Research Center, is a dubious honor: Houston leads the way among the nation’s 10 largest metropolitan areas when it comes to affluent folks living among others who are affluent, and poor living with poor. …

Of the nation’s 30 top metro areas, San Antonio, Houston and Dallas command the medals podium in Pew’s Residential Income Segregation Index. In Houston, the percentage of upper-income households in census tracts with a majority of upper-income households increased from 7 in 1980 to 24 in 2010. Likewise, low-income households in majority low-income tracts jumped from 25 to 37.

Here are maps of San Antonio, Houston, and the Metroplex shaded by income level. Each show affluence increasingly clustering in the suburbs and exurbs.

The existence of these economically segregated areas helps cement a growing class divide in the country. “The real challenge for the future of America is not a race divide but a class divide,” Stephen Klineberg, a Rice University sociologist, told Tolson. “We are heading into a world of division not by ethnicity but by class. It is becoming increasingly rigidified. The more income inequality there is, the more the upper classes live in a different world and in a different reality than the poor kids or the middle-class kids.”

John Henneberger, an Austin-based low-income housing advocate, told the Dallas Morning News‘s Michael Young that if this stratification continues unchecked, it could have dire consequences. “[N]ot going … just for the families and children in these neighborhoods, but for the entire economy — more crime, more social disruption, the need for more prisons,” he said. “If we invest in people and allow them to grow up in safe environments, we’ll pay less in the long run.”

The Huffington Post‘s James Sunshine pointed out the irony of the top three cities being in Rick Perry’s Texas, a state the governor has repeatedly held up as an example of an “economic miracle.” 

And neighborhoods are not just becoming more economically similar. At Slate, Matthew Yglesias notes that this study “follows on the heels of a bunch of other evidence that neighborhoods are becoming more homogenized along a number of dimensions. I’ve seen studies indicating that neighborhoods are much more likely to be overwhelmingly Democratic or overwhelmingly Republican.”