Here are the Newspeak translations:
• “Large body” means “five studies,” selected out of 20 rigorous experimental and quasi-experimental evaluations that exist on private school choice in the U.S. The authors claim the commentary relies on six studies but one of the supposed studies is a commentary by Mark Dynarski and Austin Nichols that discusses the other actual studies. So “six”, in Newspeak, means “five,” which somehow is a “large body.” Got it?
• “All of which” means “some of which,” as the multi-year Louisiana study cited (of which I am co-author) reports no significant achievement impacts of the program after three years and the Indiana study cited reports that the initial negative results of that program turn positive in reading by year four.
• “Worse than their peers in public school” is incorrect for all five studies. For the Louisiana and DC studies, the analyses compare students who won a voucher lottery to students who lost a voucher lottery. In both places, some of the students who lost lotteries enrolled in private schools anyway but remained in the randomized control group for purposes of calculating the effects of the program. Even more of the control group members attended high-performing public charter schools in their communities after losing the lottery. True, charter schools are “public” schools, but they are special kinds of public schools and should be described as such (at least in Oldspeak). In the Indiana study, the most rigorous program estimates come from an individual fixed-effects analysis, where the achievement gains of students while in the voucher program are compared to their achievement gains when not in the program. They are not compared to their peers but to themselves. The Ohio study matched EdChoice students with descriptively similar public school students at baseline and kept every student in their original group after that, regardless of who in either group actually attended private or public schools. These studies are rigorous precisely because they do not simply compare voucher students with “their peers in public school.”
• “Especially in math” means “almost exclusively in math.” The only lasting negative reading effect in this selective set of voucher studies comes from the Ohio study. The DC study, which is the focus of the commentary, only observes negative effects in math.
The report, from the Center for American Progress.