Review of Searching for the Tipping Point: Scaling up Public School Choice Spurs Citywide Gains

Key Takeaway: PPI report misleads on the impact of charter schools on district-run public schools, using incomplete research methods to support its policy recommendations.

GRAND RAPIDS, MI (December 3, 2024) - A recent Progressive Policy Institute report purports to examine the impact of charter schools on the achievement of students who remain enrolled in district-run public schools. Based on the data in the report, however, it shows only a weak relationship between the presence of charter schools and increases in achievement for all students, which contradicts the report's claims.

The report is centered around a graph that depicts a strong positive relationship between the percentage of students enrolled in charter schools and decreases in the achievement gap (as measured in test scores) for all low-income students in selected cities. In his review of Searching for the Tipping Point: Scaling up Public School Choice Spurs Citywide Gains, David R. Garcia of Arizona State University ran a correlation analysis using the data provided in the report and discovered that the relationship depicted in the graph is, in fact, weak (r = 0.4).

Further, while the report recognizes that correlations do not indicate causation, it still erroneously asserts that the presence of charter schools in a city, alone, has a "spillover effect" related to improvements in the academic achievement of students who are not enrolled in those charter schools.

Garcia's review points to other concerns as well, but he concludes that the report's major flaw is its incorrect depiction of a strong relationship, in the districts studied, between the presence of charter schools and decreases in the achievement gap. Also, the policy recommendations are based on an enormous, unsubstantiated causal leap, and the report makes no effort to close this gap in logic in support of its recommendations. The report should not be considered a credible contribution to policy.

Find the review, by David Garcia, at:

https://www.greatlakescenter.org

Find Searching for the Tipping Point: Scaling up Public School Choice Spurs Citywide Gains, written by Tressa Pankovits and published by Progressive Policy Institute, at: https://www.progressivepolicy.org/searching-for-the-tipping-point-scaling-up-public-school-choice-spurs-citywide-gains /

NEPC Reviews ( https://nepc.colorado.edu/reviews ) provide the public, policymakers, and the press with timely, academically sound reviews of selected publications. NEPC Reviews are made possible in part by support provided by the Great Lakes Center for Education Research and Practice: https://www.greatlakescenter.org

The mission of the Great Lakes Center for Education Research & Practice is to support and disseminate high-quality research and reviews of research for the purpose of informing education policy and to develop research-based resources for use by those who advocate for education reform.

Visit the Great Lakes Center website at GreatLakesCenter.org

Contacts

Michelle Renee Valladares

David Garcia