Study examines public, private schools

Students at independent private schools and most parochial schools scored the same on 12th-grade achievement tests in core academic subjects as those in traditional public high schools when income and other family characteristics were taken into account, according to the study by the non-partisan Center on Education Policy.

While the finding is in line with a handful of recent studies, it's at odds with a larger body of research that has found private-school students outperform those in public schools. Some of that research found a private-school advantage even when income levels are taken into account. However, the new study not only compared students by income levels but also looked at a range of other family characteristics, such as whether a parent participates in school life.

"When these were taken into account, the private-school advantage went away," the report states. In trying to determine whether the type of high school attended by a student made a difference academically, the new study tried to separate out the effects of income; earlier eighth-grade test scores; parental expectations; whether parents discuss school with their children and whether parents participate in school activities.

When all these factors were accounted for, the only kind of private schools that had a positive impact on student achievement were Catholic schools run by holy orders such as the Jesuits. Such schools have more autonomy from the church than most Catholic schools, which are typically run by a diocese and are overseen by a superintendent in the local bishop's office.

The researchers found:

All the students in the study were financially poor and fit the demographics of those who would be eligible for the kind of private-school voucher programs or other school-choice initiatives generally favored by conservatives.

However, the study shows that family involvement matters more than whether a student goes to public or private school, said Jack Jennings, the center's president.

"People commonly believe private schools are just inherently better," Jennings said. "We're forgetting that families are key to how well kids do. Maybe we ought to start to spend more time on families."

Advocates for encouraging more parental participation in schools say policy makers could boost funding for translators at schools in immigrant communities and could provide tutoring for adults who want to keep up with their kids' studies.

Andrew Coulson, an education expert at the Cato Institute, a libertarian think tank, said this one study shouldn't sway public policy.

"The overwhelming body of research favors private schooling over public schooling," he said. Coulson said he hadn't read the study but said one concern is that it looks at 12th-grade students. He said kids who enter 12th grade in many urban public schools are a higher achieving subgroup than a school's larger student body, because of high drop-out rates in many inner-city schools.

The new study did find that students at independent private schools, not the religiously affiliated schools, got higher SAT scores than public-school students.

Wenglinsky said the private schools might be doing a better job at preparing students for that college entrance exam. Or, he said, they might be enrolling students with higher IQ levels. Aptitude tests like the SATs are more closely tied to IQ scores than achievement tests.

Private-school students are more likely than those in public schools to get into elite colleges because of these higher SAT scores. However, private-school students are no more likely to attend college generally than their public-school counterparts, the study found.