Flawed Research: Private vs. Public Schools

We have great public schools all across the country.

PUBLIC AND PRIVATE HIGH SCHOOLS DO ABOUT THE SAME ACCORDING TO REVIEW OF TWO NEW REPORTS

EAST LANSING, Mich.– Two new reports appear to come to different conclusions about whether private schools are better than public ones at educating students. But a new review of both reports finds little actual difference between their findings—and little difference between public and private schools.

One of the two reports reviewed was released by The Center on Education Policy (CEP) and is entitled, “Are Private High Schools Better Academically than Public High Schools?” The other was released by the Milton & Rose D. Friedman Foundation (Friedman) and is entitled, “Monopoly Versus Markets: The Empirical Evidence on Private Schools and School Choice.” The two reports are similar in that they each use an existing national database and compare public and private schools in terms of students’ learning outcomes as measured by standardized tests.
The two reports were reviewed for the Think Twice project by Jaekyung Lee, associate professor at the State University of New York at Buffalo.

Using the National Education Longitudinal Study (NELS) database, the CEP report found no advantage for either public or private schools. The study examined schools serving disadvantaged students in urban settings.

Using the Educational Longitudinal Study (ELS) database, the Friedman report presents evidence that private schooling produces a benefit that Lee describes as “very small in absolute terms and its practical significance is questionable.” The Friedman report presents its findings in a way that makes this benefit appear more significant by applying the same gains found in the last two years of high school to all 12 years of schooling. Lee points out that without additional research, “these assumptions cannot be reasonably made.”

Lee notes that the specific findings of the two studies do not, as a practical matter, greatly differ. Setting aside some concerns he raised regarding each study, Lee explains the small practical significance of the benefits presented in the Friedman analysis. He further explains that even though the CEP analysis shows no overall private school benefits, it does show some that two types of private schools show some positive outcomes: non-religious private high school students obtained higher SAT scores than public school students, and Catholic schools run by holy orders such as the Jesuits had nominal positive academic effects.

Lee also presents his own, independent cross-examination of the two data sources and shows that the public-private high school gaps in math achievement gain scores were almost null (in the NELS) or too small to be practically significant (in the ELS). He concludes that much of the apparent differences between the reports can be accounted for by their use of different datasets, time periods, and target populations, among other things.

In the end, Lee says, while both reports may prompt discussion over the nature of school success and the values underlying school choice, both seem unlikely to adequately guide educational policymakers, practitioners or parents due to their inability to fully account for observed gaps (or the lack thereof) between public and private schools. The most that can be concluded from the two reports taken together is that “students generally learn in public high schools about as well as in private high schools, but … there are still many unanswered questions about potential differences in the finer details.”

Find the complete review by Jaekyung Lee as well as links to the CEP and Friedman reports at: http://www.greatlakescenter.org/.