A new report from the Pew Research Center describes the rise of residential segregation by income across the country, and in 27 of the nation’s 30 largest metropolitan areas, over the past 30 years.
The researchers found that the percentage of lower-income households (defined in this report as those with an annual income below 67% of the national median household income) living in majority lower-income census tracts increased from 23% in 1980 to 28% in 2010. Over that same time period, lower-income households became increasingly likely to live in tracts with more lower-income households. In 1980 the average lower-income household lived in a tract with 39% lower-income households, while in 2010 that number was at 41%.
The authors also found that the number of majority lower-income census tracts increased from 12% of all tracts in 1980 to 18% of all tracts in 2010. These tracts, however, have not necessarily become more highly concentrated with lower-income households. On average, the average majority lower-income tract contained 60% lower-income households in 1980 and 61% in 2010. The authors suggest this implies that more lower-income households live in majority lower-income tracts simply because more such tracts exist, not because they are more concentrated in a stable number of tracts.
On the other end of the income scale, the researchers found that more upper-income households (defined in this report as those with an annual income above 200% of the national median household income) live in majority upper-income census tract in 2010 than did in 1980. The percentage of such households located in a majority upper-income census tract increased from 9% in 1980 to 18% in 2010. In 1980, the average upper-income household resided in a tract with 25% upper-income households; this increased to 32% in 2010.
The researchers conclude that the increase in residential segregation over the past 30 years is related to the consistent rise in income inequality. Income inequality, based on the Gini index, a widely used measure of inequality, increased 16% from 1980 to 2011. The number of middle income households dropped from 54% in 1980 to 48% in 2010, while the share of upper-income households rose from 15% to 20% over the same time period.
The report uses data from the decennial census and the 2006-2010 American Community Survey. The report also highlights these trends in the nation’s 30 largest metro areas, characterized by the metropolitan areas with the largest number of households.