Study: Louisiana vouchers produce poor results

A new study of a Louisiana school voucher program should get attention in Indiana, where a five-year-old voucher program continues to grow rapidly with little oversight from state officials.

The study, published in December 2015 as a working paper by the National Bureau of Economic Research, finds that Louisiana students who get state-funded vouchers to pay private school tuition perform much worse on standardized tests than if they had stayed in public schools.

The voucher program, called the Louisiana Scholarship Program or LSP, was established as a pilot program in 2008 and greatly expanded by Gov. Bobby Jindal in 2012. According to the study:

Attendance at an LSP-eligible private school lowers math scores by 0.4 standard deviations and increases the likelihood of a failing score by 50 percent. Voucher effects for reading, science and social studies are also negative and large. The negative impacts of vouchers are consistent across income groups, geographic areas, and private school characteristics, and are larger for younger children.

A 50 percent increase in the likelihood of getting a failing score in math is a lot. Lowering scores by 0.4 standard deviation is harder for us non-statisticians to grasp. But note that it’s five to 10 times as big an effect as the charter-school test-score gains that are touted as meaningful by the Stanford-based CREDO research organization. So yes, it should get notice.

Most previous studies of school voucher programs have found little academic impact, with some studies finding modest gains for voucher students. But voucher programs are relatively new and varied, and the authors — economists Atila Abdulkadiroglu of Duke University, Parag A. Pathak of MIT and Christopher R. Walters of the University of California, Berkeley — say more research is needed.

The Louisiana program was ideal for study because it grew so fast that, in many cases, more students applied for vouchers than the voucher-accepting private schools had room for. The state used lotteries to determine which students got the vouchers, allowing for a “random assignment” study in which researchers could compare the performance of lottery winners and losers.

Otherwise, the Louisiana voucher program is similar in many ways to Indiana’s. Students qualify if their families make up to 250 percent of the federal poverty level and if they previously attended a public school that received a grade of C or lower or if they are starting kindergarten.