Martin Carnoy, a professor at Stanford Univ. has studied education systems around the world. he wrote this report for the Economic Policy Institute about the efficacy of vouchers. He reviews the longest-running voucher programs in the U.S. and other countries ."This report seeks to inform that debate by summarizing the evidence base. Studies of voucher programs in several U.S. cities, the states of Florida, Indiana, Louisiana, and in Chile & India, find limited improvements at best in student achievement & school district performance from even large-scale programs. The lack of evidence that vouchers significantly improve test scores, coupled with the evidence of a modest, at best, impact on educational attainment (graduation rates), suggests the ideological preference for education markets over equity and public accountability is what drives the push to expand voucher programs."