The Effect of Charter Schools on Student Achievement: A Meta-Analysis of the Literature

Three years ago, Julian Betts and Emily Tang surveyed the charter-effect literature, finding “large-scale heterogeneity in program efficacy”: Some schools outperformed their district peers while others floundered in comparison—though the overall effect of charters was still positive. This updated meta-analysis of charter-effect studies shows that little has changed since 2008. Evaluating all experimental (lottery-comparison) or student-growth studies, the authors find favorable charter-school effects (even when studies of KIPP schools were scrubbed from the dataset) for elementary and middle school math. (The effect on elementary and middle school reading is also positive, but not significantly so; those on high school reading and math are minimal.) And for other factors, like attendance rates and behavior, charter effects are significantly positive. Further delineating the studies, Betts and Tang find urban charters to be more able to lift student achievement than their suburban peers—especially schools in Boston and New York. Yet, even with three years’ more data in hand, the authors caveat their findings: The research landscape is still sparse, they explain, with studies limited by sample size, geographic narrowness, and a disproportionate focus on the KIPP schools. To really understand the variance of charter-school success, it will be imperative to undertake school-level research meant to ID specific successful practices. Still, to those who continue to insist that charter schools “don’t work” we say: “You’re wrong.”