Do charter schools work? Getting good statistical evidence is tough because parents who work to get their kids into a charter school are special (If you haven’t already, go see Waiting for Superman). We might expect their kids to outperform others whether the charter school is really superior or not. A recent article by Joshua Angrist, Susan Dynarski, Thomas Kane, Parag Pathak, and Christopher Walters took a really clever approach to untangling the devoted-to-education-parent effect from the real charter school effect.
Because it was oversubscribed, the Lynn, Massachusetts KIPP charter school chose students by a random lottery. Admitted students and those turned away all had parents who’d gone to a special effort, so we know that the outcome of getting in would be due to the school rather than parental differences. The authors were able to use the Massachusetts student-tracking system to look at later test results for lottery winners and losers. Bottom line? The kids who lucked into KIPP Lynn substantially outperformed those who lost the lottery.