In 2011, Stanford University educational sociologist Sean Reardon and his Cornell University colleague Kendra Bishoff showed that while in 1970, only 15 percent of families lived in neighborhoods classified as affluent or poor, by 2007, 31 percent of families lived in such neighborhoods. By 2007, fewer families lived in mixed income communities. In a companion study, Reardon also demonstrated that along with growing residential inequality is a simultaneous jump in an income-inequality school achievement gap. The achievement gap between the children with income in the top ten percent and the children with income in the bottom ten percent, was 30-40 percent wider among children born in 2001 than those born in 1975, and twice as large as the black-white achievement gap.
For half a century, sociologists have correlated family income with students’ test scores—wealthy children scoring higher in aggregate than their peers living in poverty. Reardon’s research helps explain just how how and why poverty and wealth are so significant for children’s outcomes. The research confirms the impact of segregated neighborhoods on student achievement and accounts for the ways that wealthy families use their money and social capital to cultivate their children. In his book Our Kids, Robert Putnam describes the significance of Reardon’s research: “In a landmark study, the Stanford sociologist Sean Reardon demonstrated a widening class gap in both math and reading test scores among American kids in recent decades… That gap corresponds, roughly speaking, to the high-income kids getting several more years of schooling than their low-income counterparts. Moreover, this class gap has been growing within each racial group, while the gaps between racial groups have been narrowing… By the opening of the twenty-first century, the class gap among students entering kindergarten was two to three times greater than the racial gap. Reardon’s…. finding is of fundamental importance, because academic achievement, as measured by test scores, is a dominant contributor to class disparities in later outcomes, such as college graduation, incarceration, and adult earnings. Strikingly Reardon’s analysis also suggests that schools themselves aren’t creating the opportunity gap: the gap is already large by the time children enter kindergarten and, he reports, does not grow appreciably as children progress through school.” (Our Kids, pp. 161-162. Emphasis in the original.)
Reardon and Bishoff continue to update their work on the correlation of growing income inequality in America with growing segregation by income—the rich moving near each other in wealthy enclaves and the families at the very bottom segregated in poor neighborhoods they cannot escape. In a follow-up report published in 2013, Residential Segregation by Income, 1970-2009, Reardon and Bischoff updated their work on residential segregation by income across our nation’s 117 largest metropolitan areas (those with populations of 500,000). Now they have once-again updated their findings in The Continuing Increase in Income Segregation, 2007-2012. Again, they study income segregation in 117 large metropolitan areas with populations over 500,000, where, they explain: “By 2012, over one third (34%) of all families lived in either rich or poor neighborhoods, more than double the percentage in 1970. Over the same time period the proportion living in middle-income neighborhoods declined from 65% to 40%… In smaller metropolitan areas, income segregation is slightly lower, but has increased at the same rate over time.” Between 2007 and 2012 segregation by income accelerated even in the middle range among working-class, middle-class and upper-middle-class families.
“Income inequality,”according to Reardon and Bishoff, ” is a key driver of income segregation.” As the family income distribution widens, the absolute differences in income between families at different points in the income distribution grow, making it less likely that lower-income families can afford to live in the same neighborhoods as those with higher incomes.” “(I)ncome segregation grew faster, on average, in metropolitan areas where income inequality was also rising quickly…. and was associated more with the rising segregation of affluence than the segregation of poverty.” In other words, families with money are moving into exurban enclaves or gentrified neighborhoods. “Many of the places where income segregation increased the most in the 2007-2012 period were metropolitan areas that prior to 2007 had low to moderate levels of segregation. In fact, in the metropolitan areas that were most segregated in 2007 (Bridgeport-Stamford-Norwalk, CT; New York-Wayne-White Plains, NY-NJ; and Philadelphia, PA), income segregation actually declined very slightly from 2007-2012.” The report ranks the metropolitan areas with the largest increase in income segregation and also those areas with the greatest increase in families living in poor or affluent areas.
The recent update on growing segregation by income from 2007-2012 concludes that, “(I)ncome segregation continued on the long upward trajectory that began in 1980. During the 2007-2012 period—which spans the start of the Great Recession and the early years of recovery—middle-class, mixed-income neighborhoods became less common as more and more neighborhoods of concentrated poverty and concentrated affluence developed… These trends may be particularly consequential for children. Neighborhood contexts and their associated resources affect children’s development and well-being, and their opportunities for future social mobility… Neighborhoods of concentrated poverty and affluence were once much less common in the U.S., but now are home to more than a third of all families in large metropolitan areas.”
The report ends with a warning not only about the consequences of growing income segregation among the poorest children but also among their isolated affluent counterparts: “Segregation of affluence not only concentrates income and wealth in a small number of communities, but also concentrates social capital and political power. As a result, any self-interested investment the rich make in their own communities has little chance of ‘spilling over’ to benefit middle- and low-income families. In addition, it is increasingly unlikely that high income families interact with middle- and low-income families, eroding some of the social empathy that might lead to support for broader public investment in social programs to help the poor and middle class.”