Sarah Theule Lubienski didn’t set out to compare public schools and private schools. A professor at the University of Illinois at Urbana-Champaign, she was studying math instructional techniques when she discovered something surprising: Private schools—long assumed to be educationally superior—were underperforming public schools.
She called her husband, Christopher A. Lubienski, also a professor at the university. “I said, ‘This is a really weird thing,’ and I checked it and double checked it,” she remembers. The couple decided to take on a project that would ultimately disprove decades of assumptions about private and public education.
Studying the National Assessment of Educational Progress and the Early Childhood Longitudinal Study, they have found that, when controlling for demographic factors, public schools are doing a better job academically than private schools. It seems that private school students have higher scores because they come from more affluent backgrounds, not because the schools they attend are better educational institutions. They write about these conclusions—and explain how they came to them—in their book, The Public School Advantage: Why Public Schools Outperform Private Schools. Here’s an interview with the Lubienskis about their work, edited and condensed for clarity and length.
Summarize what you discovered in your research.
CAL: We already know that scores for students in private schools tend to be higher. The question is, is that because they’re from more affluent families…or is that because the schools are doing better? If you go back for a generation the research suggests that there is a private school effect, that even when you control for background factors, private schools seem to be more effective, particularly for certain populations, at boosting their achievement.
So what we did, controlling for these background factors, we actually found that the opposite appears to be true and that there is actually a public school effect. Which was a surprise… We were not expecting that at all, but then digging deeper into the data, using multiple data sets, that actually held up. And since that time, other researchers—people at the Educational Testing Service, Notre Dame, and Stanford—have looked at these data sets and come to similar conclusions.
Do you agree that public schools are failing? Or is it that private schools are just failing more?
CAL: Our data says: If public schools are truly failing, then private schools are in even more trouble. But I’m not convinced that’s the case when you look at a lot of the longitudinal data and even some of the international data. There are reasons to think our typical and our best public schools are doing a pretty great job—it’s just the national averages are often dragged down by the fact that we have a lot of schools with poor-performing students who happen to also be poor. That we have such large socio-economic polarization in this country that students at the bottom are kind of skewing the overall sense of how we are doing. But there are reasons to think that over time, top scores have stabilized or even improved despite the additional challenges that are being pushed on the public schools.
STL: I would add that the NAEP data over the past couple of decades have shown remarkable improvement in U.S. students’ scores. So you know yes, public schools have challenges and have problems, but I would say that they really have shown themselves to be effective at implementing new forms of instruction and improving student achievement. And they do that with incredible demands on them to reach such a broad range of students.