Source: Mandi Woodruff for BusinessInsider.com
While revising the final chapter of my dissertation I came across some interesting data on income segregation by the Pew Research Center. Although Pew's research covers the entire United States (see 2012 report, "The Rise of Residential Segregation by Income") for this post I will focus on Washington, DC (where I currently reside).
The above map represents the Pew's Residential Income Segregation Index (RISI) for Washington, DC. RISI is calculated by adding the rate of lower-income households living in a majority lower-income tract and the rate of upper-income households living in a majority upper-income tract. Red represents lower income tracts and blue higher income tracts. Washington's score is 47 (the maximum score is 200) in comparison to the highest scoring metro areas, Houston and Dallas that have a RISI score of 61 and 60, respectively. Between 1980 and 2010, the Washington DC metro area population increased 78%, but the RISI scored only increased by 4.
The reports states that "the typical upper-income household is more likely to live alongside other upper-income households, more than two-thirds of the neighbors of the typical upper-income household in 2010 were either middle income or lower-income households." Although Pew did not report detailed data on the DC metro area, further research on gentrification in the District in comparison to the surrounding area may explain why the DC metro area has a relatively low RISI score.
It is worth noting that residential segregation by race is still more prevalent than income. The report states that "[i]n 2010, 42% of blacks lived in a census tract that was majority black, compared with 28% of low-income households living in a majority low-income tract and 18% of upper-income households living in a majority upper-income tract." This is still the case in the DC metro area. Yale Professor Bill Rankin's map illustrates the point:
Source: Radical Cartography Project