Perhaps nothing. But it’s worth exploring.

When I talk about positive charter school performance, I often include the caveat that it’s generally “urban charter schools” or “charter schools serving low-income students” that are driving these results.

The reason for this is simple: numerous high-quality studies in numerous cities document the positive results of urban charter schools; however, similar studies often find much lower performance in suburban charter schools or charter schools predominantly serving white students.

See below for CREDO’s summary of charter school effects across various subgroups:

 

As the table illustrates, charter schools achieve negative effects with white students (reading and math), Asian students (math), and non-poor Hispanic students (reading and math). 

So what’s going on?

I’ve emailed, discussed, and tweeted with some folks (including Mike Goldstein and Ryan Hill) on the issue.

Here’s some possible reasons: 

1. People in the Suburbs Care Less About Test Scores: Perhaps both suburban educators (who found charter schools) and suburban families (who send their children to these charter schools) simply care less about test score performance. If we assume that charters are often created to be an alternative to existing public schools – and if many suburban public schools already perform adequately on state tests – then the likely reason suburban charter schools form is to provide choice on some other dimension, with a de-emphasis on testing.

2. Urban Charter Founders > Suburban Charter Founders: Perhaps the founders of urban charter schools simply are more “talented” (smarts, grittiness, creative, or however one might want to define it) than founders of suburban charter schools. Under this interpretation, suburban charter school leaders want to achieve high test score performance, but they, unlike their urban counterparts, are not able to build institutions that can accomplish this goal.

3. Unobserved Selection Effects: Perhaps the students that attend suburban charter schools – while being of the same demographics as their traditional school peers – possess different unobserved traits. Perhaps they (and their families) are less conscientious, or more prone to risk-taking, than their traditional school peers, and these traits degrade their academic performance over time.

I do not know of any rigorous studies that point to one explanation over the others.

One piece of evidence that complicates the picture is the existence of some very high-performing suburban charter schools, such as Great Hearts Academies, which scored very well in CREDO’s CMO study.

Great Hearts has positioned itself as a more rigorous option than traditional public schools. At the very least, Great Hearts stands as evidence that there exists real diversity in what families in the suburbs desire for their children.

Ultimately, if I had to guess, my bet is that it’s some combination of all three of the aforementioned explanations.

It would not surprise me if suburban charters were providing a less test focused option; if on average these charters were opened by less talented founders; and if there did exist some type of unobserved selection effect.

But I don’ really know.

Bonus question: should we close a suburban charter school if parents are explicitly sending their children to these schools to sacrifice test score achievement for some other benefit?

I don’t know about that either.