Thirty Years of Charter Schools: What Does Lottery-Based Research Tell Us?

Charter schools can serve as “laboratories of innovation,” generating evidence about effective educational practices via their random admissions lotteries. This paper synthesizes findings from charter school lottery-based studies and identifies future research priorities. Evidence shows charter schools can boost academic achievement and long-term outcomes, especially for lower-performing, nonwhite, low-income students and those with disabilities. However, these findings are limited to oversubscribed schools in urban areas. Future research should expand geographic coverage, update K-12 academic outcomes, and explore non-test-score outcomes, college, and earnings. Addressing these areas would strengthen evidence and inform education policymaking in the charter sector and beyond.