Students using vouchers score no better
Nearly 2000 D.C. students who attended private school with the aid of vouchers generally performed no differently after two years time than their public school counterparts, echoing other similar research. Students also reported no higher satisfaction with private schools, although their parents did.
U. S. Dept. of Education. (2008). Evaluation of the DC Opportunity Scholarship Program: Second Year Report on Participation. Washington, DC: Author.