Celeste K. Carruthers, Urban Institute & National Center for Analysis of Longitudinal Data in Education Research
June 2009
Do charter schools siphon good teachers from mainstream public schools, or is it an unfounded accusation that we've all just grown used to hearing? This working paper by Celeste Carruthers, an economics graduate student at the University of Florida, examines data on North Carolina public school teachers (from 1997-2007) who transferred either to charter schools or to other mainstream public schools, to determine how the two teacher pools might differ. Amidst a broken record of charges against charters for "cream skimming" funds and talent from mainstream public schools, this paper prefers empirical evidence over rhetoric.
Unfortunately, like many statistical analyses comparing teacher qualifications and effectiveness, the data are mixed. On average, teachers who moved to charters were less experienced and less likely to be certified than other mobile teachers-a fact that lines up with the anecdotal evidence that young, often non-traditional educators staff many charter schools. Yet charter movers were also more likely to have at least 25 years of experience, so senior teachers were motivated to join charters, albeit probably for different reasons than younger teachers. Among certified, regularly licensed teachers, those moving to charters typically had higher licensure test scores than their colleagues moving to mainstream schools. Licensed charter movers even had higher test scores than non-mobile colleagues in mainstream schools.
The paper goes on to analyze the achievement of sub-groups of students, and determines that the effectiveness of teachers who moved to a charter school (as compared to those moving to mainstream schools) was 4.5 percent of a standard deviation higher in math, and 4 percent higher in reading. Despite this statistic, it is difficult to conclude unequivocally that mainstream schools really lose talent to charters. Teachers who decide to transfer schools may be fundamentally different from non-mobile teachers in several ways, and the latter group may deliver better student test results. Tracking the on-paper qualifications of teachers (such as certification status and licensure scores) in charter and mainstream schools can tell us what type of teacher teaches where, but questions of quality still remain unanswered.
Overall, Carruthers injects much-needed empirical evidence into debates about charter schools, the efficacy of certification/licensure, and the impact of teaching experience on student achievement. It also serves as useful fodder to counter the rhetoric-driven arguments made by Ohio's politicians and teacher unions that teacher certification and experience are necessary to improve student learning, or that charters are a wasteful diversion of funds and talent. See the full report here.
