Free to Choose: Can School Choice Reduce Student Achievement?
利用随机抽签评估路易斯安那奖学金计划，发现参与该私立学校代金券项目使弱势学生数学成绩下降0.4个标准差，阅读、科学和社会研究成绩也降低，可能因低质量私立学校被选入项目。
A central argument for school choice is that parents can choose schools wisely. This principle may underlie why lottery-based school evaluations have almost always reported positive or zero achievement effects. This paper reports on a striking counterexample to these results. We use randomized lotteries to evaluate the Louisiana Scholarship Program, a voucher plan that provides public funds for disadvantaged students to attend private schools. LSP participation lowers math scores by 0.4 standard deviations and also reduces achievement in reading, science, and social studies. These effects may be due in part to selection of low-quality private schools into the program.