Racial imbalance in charter and traditional public schools

Charter opponents have long argued that school choice increases racial isolation in America’s public schools. Earlier this month, for example, the AP released an unsophisticated analysis that supported this hypothesis. (That misleading story was swiftly discredited.) Related to this issue, Brookings has followed up a previous report, “Segregation, race, and charter schools: What do we know?,” with a study comparing the racial compositions of schools with their surrounding neighborhoods. It’s more rigorous and nuanced than the AP report, although it also risks further confusing the rhetoric in such an important and politically charged debate.

The analysts created their own measurement index for their comparison, using 2013–14 NCES Data for student enrollment and demographic information and 2010 data from the National Historic Geographic Information System (NHGIS) to determine neighborhood composition. NHGIS data are broken down into small census blocks. For purposes of this study, a school’s neighborhood includes all census blocks within two miles of a school that are also within the same school district. These demographics are then compared to school demographics to determine the “racial imbalance measure.” Each school has a racial imbalance score for white, black, Hispanic, Asian, and other race students.

The analysts determined that, unsurprisingly, U.S. schools typically have similar racial compositions to their surrounding neighborhood. Yet one third of schools were labeled “outliers,” meaning they had significant over- or underrepresentation of one or more race/ethnicity, when compared to other schools in their state. The most common types of outlier schools were those with higher black representation than the surrounding neighborhood and schools with lower white representation.

Charter schools were substantially more likely than district-operated schools to have student bodies significantly different than their neighborhoods. This was true of for white, Hispanic, and black students, but the difference was highest for the latter group: Nationwide, charters were 4.1 percentage points more imbalanced, and three times more likely to be outliers, than district schools when it came to African American pupils.

Some readers will likely interpret these data to mean that charters are more racially isolated than TPS—but that’s not necessarily so. Because the report simply compares a school’s racial composition to the surrounding neighborhood, a racially imbalanced school could actually be less racially isolated than the surrounding neighborhood. The report itself is clear in this distinction, but the headline on Brookings’s website (“60 years after Brown v. Board of Education, how racially balanced are America’s public schools?”) is decidedly less cautious.

The other major problem with the study is that it doesn’t consider the fact that most charter schools—by design—are located in urban communities. By definition cities have more population density, making it more feasible for parents to choose schools outside their immediate neighborhoods, and making a mismatch between neighborhood demographics and school demographics more likely. That’s just not the case in the spread-out suburbs or in rural areas. Thus the analysts erred in comparing charters nationwide and statewide to traditional public schools, since the former are mostly located in cities and the latter are located everywhere.

Indeed, using Brookings’ data, table 1 shows average racial imbalance scores for the largest county in each of the ten most populous cities, according to the 2010 U.S. Census. Together, these urban counties showed significantly larger imbalances for white and black students in both charter and traditional public schools than in non-urban counties. Because charters are significantly more concentrated in urban areas than TPS, this skews charters’ nationwide averages when compared to traditional public schools. Urban charters also often simply take the place of struggling district schools, thus potentially artificially shifting to charters racial imbalances that were present in the shuttered, low-performing TPS.

Finally, charters are more likely to serve higher proportions of low-income students than traditional public schools, which the Brooking study doesn’t control for but could also affect the data. In other words, if one compared charters to similarly urban, high-poverty traditional public schools—especially those that charters have replaced—the racial imbalance differences between the two school types might largely disappear.

Table 1. White and black imbalances in charter and traditional public school in highly populated and non-highly populated areas.


White Imbalance

Black Imbalance

Urban* Charter



Non-Urban Charter



All Charter



Urban* TPS



Non-Urban TPS







*Urban is defined as all schools within the largest county associated with the ten largest U.S. cities (2010 US Census).

The study also includes a number of its own caveats. Charter schools naturally have wider enrollment areas than traditional public schools, which predisposes them to racial compositions that differ from the surrounding neighborhood. Additionally, the data cannot attribute a causal relationship between charters and racial imbalance. The authors note that the relationship between racial imbalance and charters is “complicated.”

As is true with much in American education, this report underscores the dangers of generalization and oversimplification. Understanding how race and charters intersect is important for the future of school choice. But policymakers and reformers must take great care to not misinterpret or misuse these data.

SOURCE: Grover J. Whitehurst, Richard V. Reeves, Nathan Joo, and Edward Roudrigue, “Balancing Act: Schools, Neighborhoods and Racial Imbalance,” The Brookings Institution (November 2017).