The number of English learner (EL) students enrolled in public schools has grown substantially in the United States over the past two decades. How has this impacted non-EL students in those schools? New research aims to find out.
A group of RAND researchers take advantage of the fact that EL growth has recently occurred in many new communities unaccustomed to serving large numbers of EL students, which allows them to look at the impacts on a relatively clean slate. They chose the state of Delaware—whose share of ELs in public schools rose from 2 percent in 2000 (ranked 38th among all states) to 11 percent in 2019 (ranked 9th), outpacing all but South Carolina in the growth of this student population. And they analyze the school years 2015–16 through 2018–19. Student-level administrative data cover all students in grades four through eight, including their scores on state English language arts (ELA) and math test scores as well as their end-of-year summative assessments in those two subjects.
Students were sorted into five groups in each year of the study: new students, who entered public schools anywhere in the state during a given year; new ELs, who were identified as English learners in their first year of enrollment; existing students, who were previously enrolled at the start of a given year; existing current ELs, who were already in an EL program at the start of a given year; and existing former ELs, who were previously identified as English Learners but were classified out at any point during a given year. Since ELs are not randomly assigned to schools, the researchers leverage the within-school-year and across-grade variation in new EL concentration to study the effects of ELs on existing students. Because the main assignment criteria—student age—is the same for all pupils, focusing on grade bands hopefully lessens the influence of unobserved student characteristics. They also control for the effects of possible attrition among existing students who might leave in reaction to an influx of EL peers.
Overall, they find that a 5 percentage-point increase in new EL student share improved the ELA test scores of existing students in that grade level by 0.04 of a standard deviation (SD), which is statistically significant, and math scores by 0.02 SD, which is not. They found the strongest significant effects accruing to existing current ELs (improvements of 0.15 SD in ELA and math with a 5 percentage-point increase in new ELs) and former ELs (improvements of 0.08 SD in ELA and 0.012 SD in math). Other groups showed small but non-significant positive effects.
The researchers theorize that these impacts were caused mainly by a boost in classroom resources (teachers, aides, curricula, technology, etc.) deployed to support new EL arrivals, and which “spilled over” to their peers. They run dual analyses to show that the same spillover effects do not occur with an increase in the share of new non-EL students. However, this examination includes no specifics about changes in school funding amounts or spending categories, so their findings remain speculative. But their main point stands: Not only does an increase in the number of new English learner students not seem to harm the academic outcomes of current students in this context—regardless of EL status—it may even serve to increase outcomes almost across the board.
SOURCE: Sy Doan et al., “Educational Spillover Effects of New English Learners in a New Destination State,” Educational Evaluation and Policy Analysis (October 2024).
