Association for Public Policy Analysis & Management

Over the past three decades, charter schools have become the most popular form of school choice, especially in urban school districts. Since the enactment of the first charter school legislation, the number of charter schools nationwide has soared from 2 in 1992 to 7,114 in 2015, making up roughly 8 percent of all public schools. The effectiveness with which charter schools raise student achievement has been studied at length. Observational studies of administrative data find that enrolling in a new charter school has a negative impact on student achievement growth, more so in newer schools. On the other hand, recent studies have attempted to address the identification challenges by using the lottery-based admission policies to urban, oversubscribed charter schools, and find large and positive impacts of charter attendance, yet the results for nonurban charters are mixed.

In this study, we investigate the degree to which differences in teacher quality explain the effectiveness of charter schools, and in doing so, we seek to bridge the gap between research on the effectiveness of charter schools and research demonstrating the profound importance of teachers in advancing student outcomes. Despite general agreement on the importance of teacher quality, very little is known about charter teachers or disparities in teacher effectiveness between charter schools and traditional public schools (TPS) due to two important data limitations. First, in many locales, charter schools are subject to different data reporting requirements than TPS, and therefore many educational data systems lack student-teacher linkages in charter schools that are necessary to estimate teacher value-added scores. Second, despite the rapid growth of charter schools nationwide, the size of the charter school sector in many states and school districts is insufficient for adequate statistical power in a comparison of teacher effectiveness distribution across sectors. In this study, we overcome these limitations by using teacher- and school-level data from Florida.

We find that charter teachers working in above-average poverty settings have significantly higher value-added scores compared to TPS teachers serving similar student populations. We find no such cross-sector differences among schools serving more affluent students. The results also indicate that the cross-sector teacher effectiveness gaps in above-average poverty settings are mainly driven by the right tail of the teacher value-added distribution. These cross-sector teacher effectiveness gaps in urban, high-poverty settings might help explain the positive effects of attending an urban charter school on student achievement found in recent lottery-based studies.

We also find that one of the mechanisms that might be contributing to these teacher effectiveness gaps in higher poverty settings is higher returns to experience on teacher productivity in the charter sector. Our analysis of the 2011-12 wave of Schools and Staffing Survey (SASS) for teachers in Florida also provide several factors that might be contributing to cross-sector teacher effectiveness gaps including higher levels of support charter teachers receive; and higher levels of teacher influence on instructional policies and practices in the charter sector, which might lead to higher levels of teacher engagement and productivity.