Charter schoolsâ€”public schools that are exempt from many of the procedural regulations that apply to regular public schoolsâ€”are a widespread but poorly-studied form of education reform. With nearly 2,700 charter schools now educating more than 684,000 children nationwide, policymakers and parents need to know how the education charter schools provide compares to that provided by regular public schools.
Assessing the academic performance of charter schools is difficult, because many charter schools are targeted toward specific populations such as at-risk students, disabled students, and juvenile delinquents. This makes it very challenging for researchers to draw a fair comparisonâ€”comparing targeted charter schools to regular public schools is like comparing apples and zebras. As a result, there are very few reliable research findings on the academic quality of charter schools as compared to regular public schools.
This is the first national empirical study of charter schools that compares apples to applesâ€”that is, test scores at charter schools and regular public schools serving similar student populations. By comparing “untargeted” charter schools serving the general population to their closest neighboring regular public schools, we can draw a fair comparison and get an accurate picture of how well charter schools are performing.
Measuring test score improvements in eleven states over a one-year period, this study finds that charter schools serving the general student population outperformed nearby regular public schools on math tests by 0.08 standard deviations, equivalent to a benefit of 3 percentile points for a student starting at the 50th percentile. These charter schools also outperformed nearby regular public schools on reading tests by 0.04 standard deviations, equal to a benefit of 2 percentile points for a student starting at the 50th percentile.
The study’s strongest results came in Florida and Texas. In Texas, charter schools achieved year-to-year math score improvements 0.18 standard deviations higher than those of comparable regular public schools, and reading score improvements 0.19 standard deviations higher. These benefits are equivalent to 7 and 8 percentile points, respectively, from the 50th percentile. Florida charter schools achieved year-to-year math and reading score improvements that were each 0.15 standard deviations greater than those of nearby regular public schools, equivalent to a gain of 6 percentile points for a student starting at the 50th percentile.