What can the education world conclude about charter schools after their first couple of decades in existence? Something so simple that it's almost earth-shattering: The best ones benefit students enormously, especially those students who are low income, African American or still learning English. And the bad ones are far worse than if the students had stayed in their public schools. It's not hard to ensure that charter schools are good; it just takes a modicum of oversight and the political will that too many school boards have been unwilling to exercise.
Stanford University's Center for Research on Educational Outcomes recently released a sequel to its groundbreaking 2009 report that examined pairs of similar students at both charter and traditional schools and tracked their progress over the school year. The center already had demonstrated its ability to address this subject critically: Its earlier report had little good to say about charter