Charter schools benefit students in neighboring district schools

Charter schools benefit students in neighboring district schools
Positive effects found on test scores, grade completion, and more, increasing with proximity

January 18, 2018—As charter school enrollment grows nationwide, opponents have become increasingly vocal about the potential for negative spillover effects on students remaining in district schools. But in a new article for Education Next, Sarah A. Cordes of Temple University examines the effects of charter schools on neighboring district school students in New York City and finds that these spillover effects are actually positive: students attending a district school within a half-mile radius of a charter school score better in math and reading and enjoy an increase in their likelihood of advancing to the next grade. Benefits to district school students are even greater in buildings that practice co-location, in which charter and district schools operate in the same building.

Cordes analyzed 14 years of student achievement data for 876,731 3rd– through 5th-graders attending 584 district elementary schools located in the same community school district within New York City where at least one charter school served students in the same grades. She measured changes in student outcomes both before and after the entry of a nearby charter school, as well as whether these differences were larger when a charter school was closer by.

Among the key findings:

Benefits in math and reading. Students attending a district school co-located with a charter school perform 0.08 standard deviations better in math and 0.06 standard deviations better in reading, while those in district schools within a half-mile of a charter school perform 0.02 standard deviations better in both math and reading.

Decreased grade repetition. District students in co-located schools are 1.2 percentage points less likely to be retained and students at schools within a half mile are 1.0 percentage point less likely to be retained compared to students with no charter school in the neighborhood. These effects translate into reductions of up to 40 percent off the baseline grade-retention rate of 3 percent in the sample.

More charters, more benefit. Students in district schools with three or more charter schools within a one-mile radius perform significantly better in math than students with just one charter in the neighborhood, and they are also significantly less likely to be retained.

High quality, high impact. Spillover effects are larger if the charter school appears to be of high quality, defined as either having high average 4th-grade test scores or being operated by an established, respected charter management organization.

Although critics sometimes contend that charter schools sap resources and siphon off motivated students from district schools, Cordes finds that charter school entry produces no significant demographic changes in school enrollment at district schools, and that charter entry leads to a significant increase in instructional spending in district schools: 8.9 percent for co-located schools, 4.4 percent for schools within a half-mile radius, and 2.0 percent for schools within one mile of a charter school. These increases are equivalent to 50 to 125 percent of a full year’s growth in instructional expenditures.

To receive an embargoed copy of “Charters and the Common Good: the spillover effects of charter schools in New York City” or to speak with the author, please contact Jackie Kerstetter at The article will be available Tuesday, January 23 on and will appear in the Spring 2018 issue of Education Next, available in print on February 28, 2018.

About the Author: Sarah A. Cordes is assistant professor of policy, organizational, and leadership studies at Temple University.

About Education Next: Education Next is a scholarly journal committed to careful examination of evidence relating to school reform, published by the Education Next Institute and the Harvard Program on Education Policy and Governance at the Harvard Kennedy School. For more information, please visit

Last Updated


Notify Me When Education Next

Posts a Big Story

Business + Editorial Office

Program on Education Policy and Governance
Harvard Kennedy School
79 JFK Street, Cambridge, MA 02138
Phone (617) 496-5488
Fax (617) 496-4428

For subscription service to the printed journal
Phone (617) 496-5488

Copyright © 2024 President & Fellows of Harvard College