In an education system that has been equally quick to end reforms as it is to introduce them, for over 25 years the charter sector has seen significant growth. This is due in no small part to the fact that parents want charter schools as an option for their children because charter schools, on average, generate positive results for their students.
Test Outcomes
Measured by improvement on test outcomes, study after study across methods and samples, has shown that the average student in a public charter school experiences equal or higher achievement growth in English and/or math than that of a district school peer (more on research methodology) This is true for “gold-standard” randomized-assignment designs (here, here, here, here, here, here, here, here, etc.) and for quasi-experimental designs (here, here, here, here, etc.). Research has also demonstrated that charter schools perform well with traditionally underserved student populations. For example, a recent study found that Black students in charter schools gained an additional 89 days of learning in math.
To be clear, these are average effects on test-scores. There is certainly variance among charter schools in their ability to affect student outcomes with some schools performing below expectations. However, part of the charter school sector model is addressing these failures and closing schools that fail to perform. Indeed, there is research (here and here) suggesting that some of the positive effects we see from the charter sector are due to school closures. This research suggests the importance of looking at the charter sector over time, so the mechanisms of accountability can have time to influence the composition of the charter school sector. Perhaps even more important is research on policy implementation that suggests the importance of giving enough time for policies to develop and improve as implementation is better understood. This is evident in studies of Texas and North Carolina. These studies find that, over time, the charter sector improved to a point that students enrolled in charter schools, on average, outperformed their traditional school counterparts. The authors caution that this effect could be due to student sorting patterns. However, thoughtful treatment of these assumptions suggest that it is unlikely that student sorting accounts for the entirety of the effects and encourages further work on the matter.
Attainment Outcomes
The use of test scores to measure performance is a factor of both convenience and an assumption that test scores are related to attainment. Indeed, some of the best research available has demonstrated a strong relationship between test scores and longer-term outcomes such as graduation and early-career earnings. However, there is also evidence of schools influencing attainment outcomes without influencing test scores and vice versa. Because we are ultimately interested in longer-term outcomes for our students, the research base evaluating these outcomes has grown over the past decade.
This is largely because as the charter school movement ages, we can track students through high school, college, and career, but also due to better data systems allowing researchers to follow students through these transitions. Research has shown that students attending charter schools are more likely to graduate from high school (7-11% higher), attend and persist in college (10-11% and 6-13% higher, respectively), and have higher future earnings (over 12% higher). Studies have also found that female students are less likely to become pregnant in their teens, male students are less likely to be incarcerated, and students are less likely to be absent.
It is certainly worth noting that these outcomes are driven by charter schools that, on average, receive 20-40% less funding than their traditional school counterparts. These figures are even more striking when one considers that 18 states pay for the pension system before allocating funds to schools, charter schools typically must pay for facilities expenses through their operating budget, and many states have hold harmless policies that subsidize districts for students that move to a charter school. A recent study of the charter sectors in eight cities confirms the funding inequity and found that charter schools are more cost-effective and provide a larger return-on-investment than their traditional school counterparts. Though caution should be used about making linear assumption between increasing funding and student outcomes, the findings still suggest that even at lower funding levels, charter schools are delivering on their commitment to better serving their students.
Taken together, it is easy to say that, on average, charter schools are doing what they set out to do—improving educational opportunities for students. This is evidenced by the myriad of studies finding positive effects on outcomes from test-scores to future-earnings, all while operating with fewer resources. If that wasn’t enough, we estimate that there are approximately 5 million students who would attend a charter school if one was available.
Nathan Barrett, Ph.D., is the Senior Director, Research and Evaluation at the National Alliance for Public Charter Schools.
