Answer: More inequity in public school funding.

The Pew Research Center's new report "The Rise of Residential Segregation by Income" analyzes 2010 Census data to reveal that the long-term rise in income inequality over the past several decades has led to a decrease in the number of mixed-income or middle-class neighborhoods in cities across the country. With more neighborhoods becoming either poorer or richer, and with public school funding systems that are predominantly based on local property taxes, the rise of income segregation is bad news for equity and opportunity in our nation's schools. 

The report finds that income segregation has increased in the past three decades in 27 of the 30 largest metropolitan areas. 28 percent of lower-income households in 2010 were located in majority lower-income census tracts, up from 23 percent in 1980. The situation is particularly bad in some major cities like New York (41 percent), Philadelphia (38 percent), Houston (37 percent) and Los Angeles (34 percent).

On the flip side, 18 percent of all upper-income households in the U.S. were located in a majority upper-income census track, up from 9 percent in 1980. The number of mixed-income or middle-class neighborhoods has dropped from 85 percent in 1980 to 76 percent in 2010.

The Pew report notes that segregation by race and ethnicity is still more prevalent than segregation by income. But this doesn't make the latter any less important because people of color are disproportionately affected by poverty and students of color are disproportionately denied access to quality educational opportunities. (For a case in point, see this report from the Schott Foundation for Public Education on education redlining in New York City.)

So back to our central question: Why is rising income segregation bad for schools? Because low-income communities are less able than middle- or upper-income communities to provide the resources local schools need to adequately educate students. In the current economic climate with deep federal and state education budget cuts, the burden of providing for schools is falling increasingly on local communities, which leaves the most vulnerable communities at an inherent disadvantage. Rising income segregation creates sinking pockets of inequity that no amount of testing or school closings will fix. Policies that foster or enable segregation by income (for example, see this report from the Brookings Institution on zoning laws and access to quality schools) will only exacerbate the harm done to local schools and the students who attend them.

This is education redlining, a theme we've been pushing lately here in the OTL Campaign and which you can learn more about here. We need to put to an end to policies that systematically deny certain communities access to the resources and opportunities they need. We have to fight harder than ever not just for our own children in our own schools, but for the rights of all children to have a fair and substantive opportunity to learn regardless of where they live.

Click here to read more about the report and download it. And be sure to check out the accompanying residential income segregation maps of the top 10 metropolitan areas here.