Can Successful Schools Replicate? Scaling Up Boston’s Charter School Sector
AbstractCan schools that boost student outcomes reproduce their success at new campuses? We study a policy reform that allowed effective charter schools in Boston, Massachusetts to replicate their school models at new locations. Estimates based on randomized admission lotteries show that replication charter schools generate large achievement gains on par with those produced by their parent campuses. The average effectiveness of Boston’s charter middle school sector increased after the reform despite a doubling of charter market share.
We explore the roles of student composition, public school alternatives, and school practices in mediating the effectiveness of expansion charter schools. Though changes in demographic composition contributed modestly to the positive impacts of new charters, neither changes in the student body nor the quality of applicants’ fallback traditional public schools explain the pattern of results. Instead, it appears that proven providers successfully transmitted hiring and pedagogical practices to new campuses. An analysis of teacher value-added indicates that charter schools reduce returns to experience and compress the distribution of teacher effectiveness while also employing a large share of new and inexperienced teachers. These findings are consistent with the possibility that Boston’s charter schools use a highly standardized school model that limits teacher discretion, which may facilitate replicability in new contexts.