Racial and ethnic segregation in schools affects the lives of almost all American students. For decades, urban economists have espoused theories that frame segregation as the product of individual household decisions. But institutional factors, like school district boundaries, can have just as big a role.

Since the infamous 1974 Milliken v. Bradley decision, school district boundaries have acted as a barrier to diversity and equitable funding in schools, and today, more than two-thirds of school segregation in metropolitan areas is attributable to school district boundaries. To understand what this looks like on the ground, we examined elementary schools in the Hartford, Connecticut, metropolitan area. Though the Hartford region has made efforts to desegregate schools by creating magnet schools and a regional school choice program, the demographics of many neighboring districts still look drastically different.

In a recent feature, we developed a metric of how much segregation a given school contributes to its district. The Segregation Contribution Index (SCI) considers the racial and ethnic composition of a school relative to that of the school district.

The Hartford example demonstrates that adjusting school district boundaries can promote school integration if policymakers are intentional about how they draw the lines. In light of growing evidence that educational outcomes correlate to differences in school funding and race and ethnicity, wide gaps in racial and ethnic makeup across districts in the same geographic area should be a concern for equity-focused stakeholders. The potential for a school’s racial and ethnic diversity is directly limited by the racial and ethnic makeup of its local public school system. Whether or not consolidating school districts is the answer, policymakers looking to address school integration cannot overlook the role of district boundaries.

Read the full article about segregation by school district boundaries by Carina Chien and Tomás Monarrez at Urban Institute.