The significant growth of charter schools in the United States has brought both praise for the excellent results achieved by some schools and criticism that charter schools may not be serving the most disadvantaged students.
In New York City and elsewhere, a significantly smaller proportion of students enrolled in charter schools are classified as English language learners (ELL) than in traditional public schools. This observation has produced considerable discussion and some policy responses.
Though it is simple to quantify this "ELL gap" in enrollment across the charter and traditional public school sectors, we currently have very little understanding about why the gap exists. This is unfortunate: without a better understanding of the factors responsible, policymakers are more likely to adopt policies that not only fail to tackle the gap but also risk producing unintended consequences.
This paper — which builds on a joint 2013 report by the Manhattan Institute and the Center on Reinventing Public Education, Why the Gap? Special Education and New York City Charter Schools — uses longitudinal student-level enrollment data to explain the ELL gap between New York City charter and traditional public schools. Key findings include:
- The ELL gap does indeed exist. The proportion of students enrolled in charter schools with an ELL classification is significantly — and substantially — smaller than the proportion of ELL students in traditional public schools. The gap, though largest in kindergarten and first grade, is considerable at every grade level.
- The ELL gap is not primarily due to the movement of students with existing ELL classifications across the charter and traditional public school sectors, or out of New York City entirely. ELL students are less likely to exit charter elementary schools than traditional public elementary schools and no more likely to exit charter middle schools than traditional public middle schools. Moreover, ELL students are more likely to enter charter schools in nongateway grades than to exit them. ("Gateway grades" are those in which students tend to make structural moves, such as from elementary to middle school.)
- The vast majority of the ELL gap is, instead, explained by the fact that ELL students are far less likely to apply to attend charter schools in gateway grades than non-ELL students. Students with particularly poor English skills are least likely to apply to attend charter schools in a gateway grade.
- Charter schools declassify a significantly larger proportion of their ELL students than do traditional public schools. The ELL gap nevertheless narrows as students progress through grade levels because the proportion of ELL students in charter schools is, from the outset, considerably smaller than in traditional public schools.