Charter schools hurt the rich but help the poor, says a new report

A new national study on charter schools will likely have the charter skeptics cheering: Mathematica researchers have found that charter schools make no significant impact on student test scores. That’s the big takeaway, but digging more deeply, the data reveal a complicated picture of whom charter schools help, and whom they hurt.

Students who are already doing well in school would do better to stay away from charters, the study found. So would more affluent students. After two years at a charter, math and reading scores for higher-income and higher-performing students tend to drop.

For low-income students, however, charter schools can help. Poor students saw improved math scores. The study also found that charter schools in large cities are more effective at raising student math scores than their traditional public school counterparts.

(photo courtesy of Martin Lenders)

The report was directed by the Institute of Education Sciences at the U.S. Department of Education and conducted by Mathematica, a research group that just released another major charter study last week. Although many studies have tackled the charter school issue in the past — to see their conflicting findings, check out this study as well as this one — the IES says this report is the “first large scale randomized trial of the effectiveness of charter schools in multiple states and types of communities.”

However, the study doesn’t capture the complete picture of charter schools, something charter advocates are likely to point out to counter the skeptics’ cheers. The study compared only schools where there was a lottery to get in, which made it scientifically rigorous but not comprehensive. Interestingly, the charter schools in the sample had higher percentages of white and affluent students than charter schools do on average. They also served smaller percentages of low-performing students.

These characteristics may challenge how we’ve pictured the most in-demand charters, and also raises a question I asked a few weeks ago about charters that serve advantaged students.

The report’s conclusion that “not all charter schools are the same” won’t surprise many who follow the debate. What’s interesting is what the report tells us about which charter schools work better. As for why some work better than others, we’ll have to wait for the next study.

I’ll be posting an update later today with a round-up of coverage, so stay tuned..

Update

Some coverage from around the web:

Valerie Strauss at the Washington Post looks at the IES study alongside another study on charter school spending.

Education Week notes an interesting finding: regardless of the often lackluster achievement at charters, parents were more pleased with them.

And the Indianapolis Star takes an in-depth look at local charters, pointing out that the KIPP branch in Indianapolis actually performs worse than its traditional counterparts.

Sarah Garland