Dueling Studies Debate Advantages Offered by Private High Schools

Published January 1, 2008

According to a report from the Center on Education Policy (CEP), a pro-public school think tank, public high schools educate low-income students as successfully as private schools.

It’s a finding CEP said contradicts “decades of research,” and one that has come under fire from people whose studies have found private schools have advantages. One of those is a new study from the Milton & Rose D. Friedman Foundation. (See story on page 12.)

CEP’s report, “Are Private High Schools Better Academically Than Public High Schools?” used data from the National Educational Longitudinal Study of 1988 to 2000 to examine academic and nonacademic outcomes for low-income students who attended various types of high schools, including traditional public schools, magnet schools, diocesan Roman Catholic schools, and schools run by independent Catholic orders.

Factors Discarded

The study analyzed schools’ effects on achievement growth in reading, mathematics, science, and history, as well as their impact on SAT scores, college completion, civic-mindedness, and job satisfaction. To isolate schools’ effects, the study attempted to weed out the impact of family income, parental involvement, and other factors that contribute to student success over time, using regression analysis, an approach the report said differed from previous research comparing the effects of public and private schools.

According to the report’s narrative, after controlling for all contributing factors other than school type, private high schools’ advantages essentially evaporated. The study also indicated parental income and involvement and the student’s previous test scores are the biggest factors behind student success.

“Once the full scope of the family is taken into account, cultural capital as well as economic capital, private school effects disappear,” wrote study author Harold Wenglinsky, a professor at Columbia Teachers College.

Negative Implications?

Wenglinsky’s report, released in October, focused on “low-income students in urban settings–those for whom policies of school choice are often aimed,” CEP noted in its news release

Despite Wenglinsky’s conclusion, the report’s findings suggest some private schools are indeed more successful at educating low-income students than public high schools. Catholic schools run by religious orders–as opposed to much more numerous diocesan schools–were found to be better than public schools at teaching reading, mathematics, and history, and they better prepared their students for the verbal section of the SAT.

Similarly, independent private schools better prepared students for the math and verbal sections of the SAT and to complete at least some college.

‘Unacceptable’ Method

The study’s claims might not be of much value, according to Greg Forster, senior fellow and director of research at the Milton & Rose D. Friedman Foundation.

“CEP has been bragging that the outcomes of its study differ from those of the previous research because they use a different statistical method,” Forster said. “There are good reasons why nobody else has used these methods before–they’re scientifically unacceptable.”

A Friedman Foundation brief responding to CEP’s report focused on Wenglinsky’s attempt to control for parental involvement and parental expectations, noting it is very difficult to disentangle how parents and schools influence each other.

According to the brief, “It is a difficult chicken-and-egg problem, because it is likely that one of the ways private schools improve student outcomes is precisely by increasing parental involvement. … As a result, the controls CEP applies are grossly inappropriate.”

In his own study comparing private and public schools, also released in October, Forster found private high schools do, in fact, outperform public high schools. He noted “a scientifically sound” research method produced his findings.

Neal McCluskey ([email protected]) is a policy analyst at the Cato Institute’s Center for Educational Freedom.

For more information …

“Are Private High Schools Better Academically Than Public High Schools?” by Harold Wenglinsky, Center on Education Policy, October 2007: http://www.cep-dc.org/index.cfm?fuseaction=document.showDocumentByID&nodeID=1&DocumentID=226

“Monopoly Vs. Markets: The Empirical Evidence on Private Schools and School Choice,” by Dr. Greg Forster, Milton & Rose D. Friedman Foundation, October 2007: http://www.friedmanfoundation.org/friedman/downloadFile.do?id=255