Even more strikingly, in 49 cities, or over half the total where data is available, fewer than 30 percent of white students attend majority low-income schools. In just 11 cities do so few African American students attend majority low-income schools; for Hispanics, the number is just seven cities.

The trends in the patterns of schools experiencing the deepest economic isolation—institutions where at least 75 percent of students qualify as poor or low-income—further underscore the stark racial divergence in these findings. In just four cities do most white students attend schools where at least three-fourths of their classmates qualify as low-income. But most black students attend schools confronting that level of concentrated poverty in fully 51 cities; for Hispanics the number is 54.

These high levels of concentrated poverty in schools persist—and have increased overall—even in cities where there has been tremendous growth since the recession. Many advocates for low-income communities say economic isolation in the schools represents one of the most complex and consequential barriers to equalizing opportunity. “It seems to be the thing that everybody points to as the biggest challenge,” said Sarah Treuhaft, PolicyLink’s director of equitable growth initiatives. “It’s the hardest nut to crack because these issues are so deeply entrenched [due to] the housing issues that have created segregated communities. Bussing is a challenging solution. People like to attend their neighborhood schools; and there is so much pushback on integration. There are deep structural issues that can’t be tackled one at a time.”

Likewise, Reardon said it’s unrealistic to expect to bridge these disparities solely through changes in the schools themselves. “We don’t have much evidence that we can make major improvements in educational equality solely through school policy alone,” he said. “Educational policy has to be part of the picture. But we need more than that. We need to think about residential integration…we need to think about school integration, which gets easier when you have more residential integration, we need to think about increasing economic parity between blacks and whites.” In some cities, urban leaders are trying new strategies to confront these trends. They say that for a city’s economic growth to continue, they need to craft policy that ensures their own young people are equipped to compete for the jobs the city is creating.

Dallas is one city focusing more on these dynamics. “North Texas is on fire in terms of job growth, it's just been disproportionately shared in terms of who got the jobs,” said Todd Williams, the executive director of Commit! Partnership, a nonprofit working to improve college and career readiness levels in Dallas County, Texas. “Part of our issue is that we need to improve the overall quality of our schools.”