A Think Twice Review of:

Report Provides Weak Justification for Expansion of Newark Charters

Think Twice - Mar 17, 2020

Publisher/Think Tank - Manhattan Institute

Author(s) - Marcus A. Winters

A recent Manhattan Institute report attempts to estimate the effects of charter school enrollment on student test scores in Newark, NJ – a city whose charter sector has been under intense scrutiny – and finds positive effects on English language and math test scores. The report deems these effects "large" as compared to other types of educational interventions.

Reviewer(s) - Dr. Mark Weber, Rutgers University

The report's method creates a natural experiment that compares outcomes between students who were offered charter seats and those who were not. This creates strong internal validity for the report's positive test score findings. However, the generalizability of the findings is undermined by the fact that students who apply to charter schools differ significantly from the greater Newark student population. Students who are offered seats in charter schools are, for example, less likely to be English language learners or have special education needs. But the report never addresses this core issue of external validity.