Racial segregation dominated the American residential landscape for generations. We can’t afford, suggests the research of Stanford’s Sean Reardon, to let economic segregation have anywhere near as long a run.
The world’s ultra rich, filmmaker Jacques Peretti observed  last month, now inhabit “their own Elysium -style biosphere.” They live in “a floating bubble high above Earth,” a “chrome Business Class tube in the sky.”
Peretti was, of course, speaking metaphorically. The rich don’t really live in their own biosphere. They live on terra firma, just like the rest of us. But they don’t live with the rest of us. In our increasingly unequal world, those of high income live more and more apart.
Just how apart? And what does this apartness mean for the rest of us? Researchers like Stanford sociologist Sean Reardon and his collaborator Kendra Bischoff of Cornell have been exploring questions like these. Too Much editor Sam Pizzigati recently spoke with Reardon about our economic segregation — and why it so matters.
Too Much: Most people today hear the word segregation and think racial segregation. You’ve spent a great deal of time thinking about economic segregation. Why?
Sean Reardon: We’re concerned about racial segregation, in part, because of the economic segregation that goes along with it. Racial segregation often means that blacks or Latinos are unequally concentrated in poor, disadvantaged neighborhoods, with poor quality schools and institutions.
I’ve been worried that in an era of rising income inequality we may also be seeing rising spatial inequality economically. I worry about the consequences that this might have, particularly for children growing up in increasingly unequal neighborhoods.
Too Much: We can see racial segregation. Economic segregation we can’t see in the same way. How do you go about measuring economic segregation?
About one-third of Americans today live in either very affluent or very poor neighborhoods.
Reardon: A couple different ways. One is simple, and I’ve used it in research  with Kendra Bischoff at Cornell.
First, for all metropolitan area neighborhoods, we computed the ratio between every neighborhood’s median family income and the overall metropolitan area’s median income. Then we used this ratio to classify neighborhoods as either poor, low income, low-middle income, high-middle income, high income, or affluent. And then we looked at what proportion of families live in neighborhoods in each category.
When we do that, we find that in 1970 about two-thirds of all American families lived in neighborhoods that rated as middle-income relative to the larger metropolitan region. And only about one in six families in 1970 lived in very affluent or very poor neighborhoods.
Today, about 42 percent of families live in middle-income neighborhoods, and about one-third live in very affluent or very poor neighborhoods.
So we’ve seen a shift — from two-thirds to 42 percent — of families who live in middle-income, mixed-income neighborhoods. Many more families today are living in either very affluent or very poor neighborhoods. You can see this very dramatically in maps showing  the economic composition of neighborhoods over time.
We seem to be in a period where economic segregation is rapidly increasing.
Too Much: Is this shift toward greater economic segregation easing or accelerating?
Reardon: Economic segregation increased a lot in the 1980s. It didn’t change much in the 1990s, but it’s grown a lot again in the 2000s. So we seem to be in a period where economic segregation is rapidly increasing.
Too Much: Did the crash in 2008 bring on this latest increase?
Reardon: The Census Bureau’s American Community Survey — the ACS — isn’t sufficiently fine-grained, in a temporal sense, to let us now answer that question. To get a sample big enough to estimate each neighborhood’s income distribution, the ACS averages five years of data collection. So you can’t just look at 2007 before the crash and then look at 2009 because you always have a five-year moving average.
So at this point it’s hard to say what exactly happened as a result of the crash and what’s part of a longer-term trend.
Too Much: Just how does increasing economic inequality feed economic segregation?
Reardon: We have a market-driven housing world. With inequality in family income growing, families can afford to spend increasingly different amounts on housing. They end up sorting themselves more into neighborhoods that have housing at the price they can afford.
In metro areas where income inequality has increased the most, we see income segregation increase the most.
In the work that I did with Kendra Bischoff, we showed that in metropolitan areas where income inequality increased a great deal, that’s where you saw income segregation increase the most. In places where income inequality didn’t increase as much, that’s where you saw income segregation increase the least.
Too Much: So market dynamics help explain why the more affluent the affluent become, the more they live among their fellow affluent. Is there a social-psychological motor behind that growing economic segregation as well?
Reardon: There may well be. My research with Kendra Bischoff looked at housing patterns and their relationship to economic forces. But we don’t really observe people’s feelings or motivations. So I don’t have any evidence one way or another on that.
There is, however, some interesting new research from Ann Owens, a sociologist at the University of Southern California. She seems to be finding that increasing income segregation among families with children is driving most of the increase in income segregation.
Childless households — whether single people or elderly people or couples who don’t have kids — aren’t becoming that much more segregated from each other, according to Owens’ evidence.
It’s really families with children that are becoming more economically segregated, and this suggests that concerns about where children are going to grow up and what schools they’ll go to — and maybe who they’re going to play with — are interacting with income inequality to drive the patterns of income segregation.
High-income families that live among only other high-income families may have less understanding of the plight of everyone else.
Too Much: And that brings us to the notion that increasing economic segregation itself generates increasing economic inequality.
Reardon: We can imagine lots of ways increasing economic segregation could do that.
Increasing economic segregation means that kids from high-income families live with kids from other high-income families and go to schools that have more resources. They go on to do better in school and have a better chance at attending a good college.
We have evidence over the last few decades that the achievement gap — the test score gap — between students from high- and low-income families is widening, and maybe that’s related to these processes.
But I think there’s another less direct but maybe more insidious way that these things operate.
If high-income families increasingly live among other high-income families, and far away from middle class and lower-income families, then they may have less understanding of the plight of the middle class or the working class or the poor. They may be less willing to invest their resources in public goods — like schools and child care facilities and health care and infrastructure — that would broadly benefit everyone in society.
And so I worry that income segregation means that the affluent are increasingly sequestered in enclaves where they have little incentive to understand why we should invest in broad public goods that would help everyone. And since these affluent control the vast majority of our economic resources — and also a disproportionate share of our political resources — then their disinvestment from public goods has broad repercussions for our society. Kendra Bischoff and I wrote more about this possibility in a recent post .
Our affluent are increasingly sequestered in enclaves where they have little incentive to understand why we should invest in broad public goods.
Now we don’t have good evidence on the extent of this dynamic. It’s a tricky thing to trace. But it’s a potential concern that I think we should take very seriously.
Too Much: Let’s talk a bit more about your work on the achievement gap between black and white students and high- and low-income students. Fifty years ago, you’ve noted, the achievement gap between black and white students was almost twice as wide as the gap between high- and low-income students. Today’s income-achievement gap is more than 50 percent larger than the racial achievement gap. How directly do you think income and economic segregation is at play here?
Reardon: I think that many different forces, acting in concert, are determining these broad changes in racial and income achievement gaps. Economic segregation plays a role, but so do big changes in how much families invest in their young children’s education and educational experiences, growing disparities in family structure and family resources, maybe even the quality of schools.
So the growth of economic segregation may be part of the story, but I suspect there are many other parts of that story as well.
Too Much: Is income and economic segregation resegregating America along racial lines?
Reardon: No. If you look at residential patterns of racial segregation, they’ve been slowly declining over the past 40-plus years. Now some claim that these declines mean the end of racial separation, but that’s far from true. We still have enormous racial segregation in America, but it is running moderately lower than decades ago and has been steadily declining.
We’re not seeing upticks in racial segregation. We’re seeing slightly less racial segregation but more economic segregation. Those things don’t operate in tandem.
Too Much: We did, through the legal system, outlaw racial segregation in the United States. How can we attack the concentration of income and wealth that fuels economic segregation?
We don’t want to have a society of fortress communities.
Reardon: That’s the billion-dollar question. We could outlaw explicit racial segregation because of the 14th amendment. The 14th amendment doesn’t apply to socio-economic status. So there’s little leverage there in the legal system.
We need the public and political will to create a society that’s founded more on equal opportunity and less on extremes in inequality and inheritance. You can attack inequality through the tax code and job creation and policies that support the middle class and things like that. You can alter patterns of segregation through housing policy, zoning policy, and investments in neighborhood public goods like schools, and parks, and community centers. You can’t do it through the Constitution.
Too Much: If levels of income and wealth inequality keep growing in the United States, just how economically segregated can we become? If current trends continue, what do you think the United States might look like 25 years from now?
Reardon: I don’t think it’s possible for inequality and economic segregation to continue to rise indefinitely. But things could get worse than they are. And we don’t want to have a society of gated communities and fortress communities.
Too Much: Is the discipline of sociology doing enough now to come to grips with the impact of growing economic inequality?
In some ways, issues of inequality have entered the public conversation over the last few years in ways they really haven’t for decades. We’ve always had sociologists concerned about these issues — and political scientists and economists and historians and so on. What’s different now? These issues appear more in the public discourse, and that means there’s potentially some appetite and political will to do something to remedy them.
Too Much: Where are your future research interests taking you?
Reardon: Many directions. I’m interested in the relationship between educational inequality and social mobility. I’m also interested in the great geographic variations we have on inequality.
Nationally, we can see patterns of increasing income segregation, increasing educational inequality by income, and slowly declining racial disparities. But different states, different cities, and different school districts show enormous differences in these patterns.
Trying to find places where the trends are going in a more positive direction — and trying to figure out what’s leading them in that direction — can help us think about broader policies that might help create broader economic opportunity for a much wider stretch of America.
Interested in delving deeper into Sean Reardon’s inequality-related work? You can find much of it now available online .
Sam Pizzigati edits Too Much , the Institute for Policy Studies online monthly on excess and inequality. His latest book: The Rich Don’t Always Win: The Forgotten Triumph over Plutocracy that Created the American Middle Class, 1900-1970  (Seven Stories Press).