I think the conventional wisdom on charter school evidence could be summed up thusly: ”some charter schools appear to do very well, but on average charters do no better and no worse than public schools”. But I would like to propose a better conventional wisdom: “some charter schools appear to do very well, and on average charters do better at educating poor students and black students”. If the same evidence existed for some policy other than charter schools, I believe this would be the conventional wisdom.
Two of the most widely cited charter studies are a 2009 and 2013 analysis of charters in 16 and 27 states respectively by the Center for Research on Education Outcomes (CREDO). The results that many cite are the charter schools do no better or worse than nearby public schools on average, which was the conclusion of the 2009 study. However, I think this claim really missed the bigger picture. While overall charters and public schools compare relatively closely, both the 2009 and 2013 study found that charters did better for students in poverty. In addition, performance gap is growing over time: