The continuing debate over vouchers is bound to become even hotter after investigators reported contradictory results about test scores. It’s little wonder that confusion reigns.
Public school students who used vouchers to attend private schools in Louisiana and Indiana scored significantly worse on reading and math tests compared with similar students who remained in public schools (“On negative effects of vouchers,” Brookings, May 26). But researchers at the University of Arkansas who looked at 19 studies of 11 voucher programs from Milwaukee, Wisc. to Delhi, India found that voucher students posted “statistically significant” improvement in math and reading test scores - the equivalent of several months of additional learning (“Vouching for Achievement,” The Wall Street Journal, May 27).
Which side is right? Until now, most people have assumed that private schools provided a better education than public schools. But a public school student in Louisiana who was at the 50th percentile in math slipped to the 34th percentile after one year in a private school. A student at the 50th percentile in reading declined to the 46th percentile. The results were impressive because private schools with more applicants than seats used lotteries to choose applicants randomly. The performance of those who won (the treatment group) was then compared with the performance of those who lost (the control group). Moreover, students applying for a voucher were below average for the state, thereby negating the assertion that self-selection was at work.
In contrast, researchers delving into 19 studies of 11 voucher programs found that voucher students increased their reading scores by about 0.27 standard deviations and their math scores by about 0.15 standard deviations. In more understandable terms, that meant the voucher students benefited from the equivalent of several months of additional learning than non-voucher students. The 19 studies all compared a treatment group (voucher students) with a control group (non-voucher students).
Neither side’s evidence will end the debate over vouchers, nor should it. Test scores are not the only factor that parents take into account in making a choice. If they believe that traditional public schools are shortchanging their children for any reason, they have the right to send them elsewhere, even when test scores tell a different story. Of course, they have always had this right by paying for private and religious schools. What is different today, however, is that public funds can be used for that purpose as a result of the U.S. Supreme Court’s ruling in Zelman v. Simmons-Harris. The high court held that as long as public money was given directly to families, they were free to choose the kind of schooling they alone believed was best suited for their children, be it private, religious, online, or at home.
The opinions expressed in Walt Gardner’s Reality Check are strictly those of the author(s) and do not reflect the opinions or endorsement of Editorial Projects in Education, or any of its publications.