Charter Schools: Great in Cities, Ho-Hum in Suburbs?

Evaluating charter schools is tricky. Maybe highly motivated parents send their kids to charters and others don’t. The solution is to identify schools that are oversubscribed and track students who won and lost the lottery to get in. That way you get a random set of parents on both sides. But maybe charters kick out bad students after they’ve attended for a year or two. The solution is to tag lottery winners as charter kids forever. They count against the charter’s performance regardless of where they end up later. Fine, but maybe oversubscribed charters are different in some way. What about less popular charters where you can’t do any of this lottery-based research?

Susan Dynarski, an education professor at the University of Michigan, acknowledges all of this, but says we can draw some conclusions anyway:

A consistent pattern has emerged from this research. In urban areas, where students are overwhelmingly low-achieving, poor and nonwhite, charter schools tend to do better than other public schools in improving student achievement. By contrast, outside of urban areas, where students tend to be white and middle class, charters do no better and sometimes do worse than other public schools.

This pattern — positive results in low-income city neighborhoods, zero to negative results in relatively affluent suburbs — holds in lottery studies in Massachusetts as well in a national study of charter schools funded by the Education Department.

Interesting. But if this is really the case, why?