Here’s one way to think about charter performance: Despite some quality problems charters are over-represented per-capita on the U.S. News rankings of U.S. high schools, which take into account equity and achievement gaps – as opposed to some other rankings you may have heard of… Disc – I helped develop these USN rankings (an overview of the methods here and a lot of detail here (pdf)).
Update: In the comments section Allison Martell makes a great point. I didn’t mean to imply that the USN rankings indicated a higher achievement mean for charters overall, only that charters are over-represented among the nation’s best high schools (as judged from an equity and college prep standpoint). So the implication isn’t that all charters are great, rather it’s that there is some learning that can happen from these really good charters in terms of methods and efficacy.
I only mentioned the quality problems in the original post to indicate the variance. But, I don’t agree with Allison that “[c]harters are allowed more flexibility, so we shouldn’t be surprised if they are more likely to be exceptionally good, and also more likely to be exceptionally bad.” In theory that’s true. However in practice there are elements of state policy that can move the quality curve substantially to the right – good charter school authorizers, accountability for authorizers, support and fiscal equity for charters, state policies that allow and encourage high performing charters to replicate and serve more students etc…
In the end, having more charters like those that hit the board in the USN rankings requires two changes: More regulation than many in the choice community have to date been comfortable with and more charters, choice, competition and dynamism and disruption than most vested stakeholders are willing to allow right now.