Public and Private School Performance in the 2003 NAEP
The US Department of Education recently released a report comparing public and private schools. The study used the National Assessment of Educational Progress (NAEP) data, which is a nationally representative sample of public and private school students. This particular study looked 
at reading and math test performance of students in the fourth and eighth grades. Part of the results of this study were covered in today’s New York Times, which reported that fourth grade students in public schools do significantly better than fourth graders in charter schools. This result calls into question the agenda of charter schools, which, as a centerpiece of the Bush education plan, claim to be able to produce better results at a lower cost.
While the results regarding charter schools are interesting, I do want to point out a few things. First of all, the report is really about comparing all private students to public school students. The results from this overall study were equally interesting. For fourth grade reading scores, the average private school student did better in reading. After controlling for differences in student characteristics, however, the difference in reading scores was not different than zero. For fourth grade math scores, however, public school students performed better–even after controlling for the fact that different types of student attend public schools and private schools.
The real kicker, however, was what happened in the eighth grade. Remember that the controlled difference for fourth grade reading was not statistically different than zero. By the eight grade, private school students are doing better than public school students in reading, even after controlling for student differences. Furthermore, the math score advantage of public school students does not carry to the eighth grade, where adjusted differences between public and private schools students is statistically zero.
I do not want to make too much of this result, because it is not as if we are following a cohort of kids from the fourth grade to through the eighth grade. The results are simply a snapshot of students in the fourth grade and in the eight grade in 2003. That being said, the reversing results from the fourth to eighth grade call into question exactly what is happening to public school student relative to private school students as they head towards high school. In addition, coming back to charter schools, one has to ask what is different about charter schools than other private schools which makes them perform worse?
