A new study on the impact of Indiana’s school voucher program from University of Notre Dame researchers finds that students who switched to private schools using vouchers experienced statistically significant annual losses in math achievement.
The researchers, who released their report Monday, analyzed student records for public and private school students in grades 3-8 during the first four years of Indiana's voucher program from 2011 to 2015.
The study found voucher impact in English and language arts to have "no statistically meaningful overall effects." In math, the largest losses happened during the first and second years—with students regaining losses in the fourth year.
"Across nearly all subgroups of students in the disaggregated results, we find persistent, statistically significant negative impacts of receiving a voucher on average annual mathematics levels and gains," according to the research.
The findings of the study come as Indiana’s expansive program—which has been heralded by school choice advocates as a model for the nation as the Trump administration seeks to expand choice—is undergoing more scrutiny, some even from school reform advocates who are increasingly questioning the size, scope and results of Indiana’s program.
The Notre Dame researchers have had a data-sharing agreement with the Indiana Department of Education as their study progresses. The paper is currently under peer review at an academic journal—but the researchers released it early after a reporter at another media outlet acquired a version of it.
The researchers note that because Indiana does not do random assignment of vouchers, any study is "subject to selection bias."
"Choosing to apply for and receiving a voucher depends on the active choices of parents and their children," the study notes. "For example, if students with high aptitude or motivation apply for and receive a voucher, then the performance of voucher students might appear better than non-voucher students because of potentially unobserved background differences between students."
The report also noted that the results were similar for students of color and for white students. Other voucher studies have shown statistically significant gains for some sub-groups of students.
"These findings raise questions about the mechanisms that may explain these negative effects, such as the mathematics curriculum, instruction, or teacher quality in private schools not being as robust as is found in public schools," according to the report. "At the same time, these results could also point toward issues with changing schools and sectors."
Indiana's voucher program—which now serves about 3 percent of the state’s K-12 students—has grown significantly since it took off, and the program's demographics have changed along with it. This year the state is expected to spend about $146 million on voucher payments to schools.
Fifty-five percent of the nearly 34,500 recipients this year never attended an Indiana public school. The program has also become more white and more affluent along the way, although there are still income restrictions on the program.