In the 2017-18 school year, 35,458 Indiana students received vouchers to attend 318 private schools in the state through the Indiana Choice Scholarship Program, the largest such program in the United States and one that is aimed specifically at low- and modest-income families. (The amount of tuition paid was based on family income.)
A study by R. Joseph Waddington and Mark Berends has found that the program did not have the desired effect of improving student achievement. In fact, test scores on the state’s mathematics exam showed that these students achieved less growth than similar students who remained in public schools. That effect persisted over the following three years. The authors note that these findings are consistent with studies of programs in Louisiana, Ohio, and the District of Columbia. The researchers also studied English language arts scores, but the differences were not statistically significant.
Source: Waddington, R.J. & Berends, M. (2018). Impact of the Indiana Choice Scholarship Program: Achievement effects for students in upper elementary and middle school. Journal of Policy Analysis and Management.