Charter schools under-perform public schools, a recently released government study reports.

The U.S. Department of Education’s National Center for Education Statistics study compared 4th grade math and reading tests in charter and public schools. Public school students scored significantly higher in both math and reading than their charter school counterparts.

Charter schools are publicly funded, privately run schools that can be sponsored by a variety of entities, from school districts to for-profit businesses, depending on state law. Approximately 2,700 charter schools operated in 36 states in 2003. The number has now jumped to more than 3,600.

After the report was released, Education Secretary Margaret Spellings tried to downplay its findings, saying, “Many charter schools are still relatively new, and we need to examine how they improve student performance over time for a better picture of how they compare to traditional public schools.”

However, data released with a previous NCES report indicated that students in older charter schools performed no better than their counterparts in newer charter schools.

The Department of Education web site states that the National Assessment of Educational Progress, also known as the “nation’s report card,” is the only nationally representative and continuing assessment of student performance in the schools. The latest charter school study was based on 2003 NAEP data.

State participation in NAEP is required under the Bush administration’s controversial No Child Left Behind Act, passed in 2001. Under that law, conversion to charter status is one potential “remedy” for public schools that receive failing grades several years in a row.

Education advocates note the government’s own reports run contrary to Bush administration policies, which support privatization of public education through vouchers, charter schools and other measures.

The vast majority of Americans prefer improving public education through reforming the existing system rather than replacing it, according to the Phi Delta Kappa/Gallup Poll’s 38th annual survey of public attitudes toward public schools.

Commenting on the latest report, American Federation of Teachers President Edward J. McElroy said it “provides further evidence against unchecked expansion of the charter school experiment.”

NCES commissioner Mark Schneider said the new study, and the earlier NCES study that shed a negative light on private schools as compared to public schools, are inappropriate for his agency. He said the analysis relied too heavily on subjective judgments. The department has no plans to replicate the analysis with the 2005 or 2007 NAEP results, he said.