Public vs. private

When similar students are compared, public school students in fourth and eighth grade score nearly as well in reading and math as private school students, reports a study done for the National Center for Education Statistics. However, private students do better in eighth-grade reading and public students do better in fourth-grade math.

Overall, children in Lutheran schools did the best, while children in conservative Christian schools did the worst, when compared to children of similar race, ethnicity, socioeconomic, English fluency and disability status.

A version of the study released in January focused only on math scores.

The report’s caveats sections downplays the results, calling them “of modest utility.” Chad Colby, an Education Department spokesman, repeated the “modest utility” phrase in discussing the findings.

Why do conservative Christian schools underperform public schools? I suspect it’s because parents are choosing those schools for religious values, not primarily for academics. In addition, these schools tend to be run on a shoestring.

Update: On Political Animal, Kevin Drum critiques the study, observing that public school students tend to do OK in elementary school but falter in secondary school.

Update II: In a Wall Street Journal story (registration required), Paul Peterson questions whether the study accurately counted the number of private-school students from non-English-speaking homes or with disabilities.

Paul Peterson, a Harvard University government professor who has long supported voucher programs, said that some of the study’s adjustments for student characteristics were invalid. In particular, Prof. Peterson said that public-school students were more likely than private schoolers to be counted as speaking English as a second language or in need of special education.

In examining the same data, Prof. Peterson said, he found that “when we rely on the student’s own report of whether the family is speaking English at home or not, the private sector advantage becomes clear.”

I wonder how accurate the family income statistics are since they’re tied to the federal school lunch program.

About Joanne


  1. Quoth the maven: “I suspect it’s because parents are choosing those schools for religious values, not primarily for academics.”

    Which is another way of saying that the students being compared aren’t similar.

  2. Mike in Texas says:

    And in math, 4th graders attending public school were nearly half a year ahead of comparable students in private school, according to the report.

    I wonder how the administration will try to spin this into anti-public school sentiments?

  3. Chris C. says:

    “Which is another way of saying that the students being compared aren’t similar.”

    You can statistically control for these differences, of course, and that’s exactly what ETS did in this study. These results suggest students in conservative christian schools are achieving less than comparable peers in other school settings.

  4. Obi-Wandreas says:

    My wife asked the question “what is meant by ‘Conservative Christian’ schools?” I downloaded the entire document and there is no sign of what constitutes a “Conservative Christian” school. It would be easier to judge if they defined what they were talking about.

  5. Mike in Texas says:

    Of course, Joanne left out the part where Kevin Drum explains why he critiques the report.

    But what does seem to show up over and over again is the effect of concentrated poverty. Nearly everything I’ve read suggests that when the number of kids in poverty reaches about 50% in a school, teaching becomes nearly impossible — and that this matters much more in secondary school than in elementary school.

    Poverty is the only element high stakes tests measure with any accuracy. It is nice to see that someone in the media is beginning to realize its importance.

    While I disagree that a 50% poverty level makes teaching impossible, I do believe it complicates it and requires additional resources to overcome it’s effects.

  6. Kevin Drum did not claimed “Poverty is the only element high stakes tests measure with any accuracy.” In fact the study is based on these kinds of test. If the test does not really measure performance, then the the study is meaningless.

    There is no question that poverty can be an obstacle to education. Kevin said that pedagogy wars don’t really matter much. This is probably true, but neither does throwing money at it help much. What we need is a change of culture, attitude from the students and parents.

  7. Mike in Texas says:

    I realize that BD, that is why that statement is not in the block quote. I agree with you when you say, “What we need is a change of culture, attitude from the students and parents.”

  8. Yesterday I helped my son to go through some example problems in his chemistry textbook. Every sample problem has 3 steps:

    Plan a problem-solving strategy.
    Apply the problem-solving strategy.
    Do the result make sense?

    The last step is very important, it offers a sanity check on you work.

    That is how I feel about the study. The best way to do the study is to track the individual student, to see how the same student do when he goes to public school and private school. Of course such data are not available for the study. But we can make a guess. Nobody force you to send your kids to a private school. In fact doing so usually requires extra financial and time commitment from the parents. I send my kids to public school because I am not willing to make such a commitment. If the parent sees that their kids are learning less, wouldn’t they quickly send their kids back into public school.

    The study statistically controlled individual student characteristics and school characteristics such as school size. We know that private schools and charter schools are usually smaller than public schools. So the study has to either compare private schools with only small public schools, or to adjust the scores according to school size. Now are we doing a meaningful comparison any more? Statistically controlling individual student characteristics make sense, but school characteristics should not be. Otherwise it is like saying: if the private school is just like the public school, then you would be better off going to public school. Of course it is true.

  9. Although study adjusted for “selected student characteristics”, the adjustment itself is yet another source of possible error. Would we all agree on the selection of student characteristics, as well as on the adjustment mechanism?

  10. zdomain says:

    Some of what I would classify as “Conservative Christian” schools are indeed run on shoestring budgets, with few licensed teachers, self-study curriculum, and a lack of discipline. Some schools won’t handle discipline problems because they are afraid of loosing the tuition dollars. Even though my wife and I would classify ourselves as “Conservative Christian,” we wouldn’t automatically send our children to such a school. I guess from what I have seen of these schools, the results don’t surprize me.

  11. “Otherwise it is like saying: if the private school is just like the public school, then you would be better off going to public school. Of course it is true.”
    That could be true but that’s not what the data say. One critical step in this technique is building a “student-level” model without controlling for school characteristics other than the ‘school type’ variable that is of central interest. These results are published and you can check it out online for free. There are two important points to note:

    1. Controlling for school characteristics doesn’t really explain much anyway. Student-level variables (such as ethnicity, home characteristics, and whether or not the kid has a disability) are really much more important.

    2. Even if you don’t control for those characteristics, the “school type” is still often a significant predictor of student achievement. For example, whether or not you control for school characteristics doesn’t really change the fact that schools that self-identify as “conservative christian” have much lower math achievement in 8th grade.

    And Bart, I’m guessing we all would agree. They are listed on page 7 of ths report. Let me know if anything looks suspect to you. The controls are all statistically signficant predictors of student achievement and they are all very common controls in studies with this dataset.

  12. Indigo Warrior says:

    Did this study even consider that Lutheran schools (e.g.) may attract and best serve students of a certain personality type, while Baptist schools (e.g.) another type? And that if these students were forced to switch, they would do much worse?

  13. is this study similar to the one that come out a few months ago saying that public school are as good as charter when they fudge sorry adjust for seperate factors. I’m not from missouri but show me the data, the report is irrelevant, it is essentally someone interpertation of the data, also how they fudged it.

  14. Well I just conducted a study of parents with kids in school and the results were striking. Turns out 100% of parents with kids in private/charter schools actually want their kids to be there.

    I’m grappling with the implications of the study right now, trying to determine whether this is just a case of correlation without causation or whether there’s some underlying effect at work.

  15. Ron K,
    No, but the there was a study of private schools versus public schools several months ago with similar conclusions. Similar methods and same data but a different research team.
    And they do “show you the data”. The variables they controlled for, data descriptives, etc. are all available on the web. Free and accessible:

    Allen, I don’t find the results surprising and don’t think there are huge implications except that private schools are not a silver bullet for higher achievement. I think parental satisfaction of a school has a lot to do with other factors beyond reading and math achievement – enrolling similar students in public or private schools don’t seem to have a huge effect on achievement. There are exceptions, of course – this is just a generalization.

  16. I don’t find the results all that surprising either although I suspect for different reasons and, I think private schools are a silver bullet for higher achievement provided they don’t have the shelter of the low standards of the public education system.

    But if private schools, or parental choice which is the pivotal factor, aren’t the silver bullet then what is?