Students’ math scores drop for years after using a private school voucher in country’s largest program

Low-income students who use a voucher to attend private school in Indiana see their math scores drop for several years as a result, according to a new study.

“Our results do not provide robust support that the [voucher program] has been successful to date at improving student achievement for low-income students who use a voucher to switch from a public to a private school,” conclude the researchers, Mark Berends of Notre Dame and Joseph Waddington of the University of Kentucky.

The paper, focuses on the initial rollout of what has become the largest school voucher program in the country. In the most recent school year, over 35,000 students were enrolled in the initiative.

The study examines a few thousand low-income students who switched from public to private school using a voucher starting in the 2011-12 school year.

Notably, the authors show that low-income students who used a voucher had slightly higher starting test scores than low-income kids who stayed in public schools. This gives credence to fears that a voucher program could concentrate the most disadvantaged students in the public school system.

The authors attempt to control for these and other factors to isolate the effect of attending a private school. (Unlike some voucher studies, this paper is not able to compare students who randomly won or lost a chance to attend private school — a stronger method.)

In math, the results, which focus on grades five through eight, are consistently negative. Even four years into the program, students who use a voucher had lower test scores than public school students.

In English, there were no clear effects. Here, there was some evidence that voucher students improved over time, though there were no statistically significant positive effects after four years.

The results were generally consistent for students of different races, genders, and locations. The findings, though, might not hold for more affluent students or the increasing numbers of participating students who never attended a public school to begin with. Neither group is accounted for in this study.

The results, published this week in the peer-reviewed Journal of Policy Analysis and Management, are largely in line with an earlier version of the same study — with a key exception. The first paper suggested that declines in math disappeared for students who used a voucher for multiple years. The latest version finds that the negative effects seem to persist for at least four years.

The results, then, undermine the argument that recent studies showing drops in voucher students’ test scores just represent students adjusting to private school. A recent study in Washington, D.C. showed substantial drops in math achievement persisted into a second year. Negative results also were consistent in an Ohio voucher study. In Louisiana, math and reading test scores bounced back according to one method but not another after three years; drops were consistent in social studies.

Voucher advocates have responded by arguing that tests should not be the sole judge of these programs’ success, pointing to more favorable research looking at high school graduation and college enrollment. Despite test score declines, a recent study showed that Louisiana’s program had no effect or somewhat positive effects on college enrollment.

“Although academic achievement outcomes are important for researchers, policymakers, and practitioners to consider, parents make schooling decisions for their children based on a multitude of factors, including academics, location, safety, and religion,” Waddington and Berends write. “Therefore, researchers need to examine outcomes beyond test scores.”

Critics might also point to other concerns not captured in the study: A Chalkbeat investigation in 2017 found that about one in 10 Indiana private schools that accepted a voucher had policies that explicitly discriminated against LGBT students.

That’s perfectly legal under Indiana’s system, as well as the vast majority of publicly funded private school choice programs.