Do Disadvantaged Urban Schools Lose Their Best Teachers?

Recent research documents substantial variation in teacher quality as measured by value added to student achievement, much of which is not captured by characteristics typically used in the hiring and salary determination processes including post-graduate schooling and experience. Consequently an understanding of the impact of teacher transitions on school quality cannot focus simply on such observed characteristics. This paper begins by estimating the variance in teacher value added for a large urban district in Texas using methods that mitigate bias potentially introduced by test measurement error and by the nonrandom allocation of students among classrooms. It then describes average differences in value added between teachers who switch schools within or across districts, exit the Texas public schools altogether, or remain in the same school. The results show significant variation in teacher value added after allowing for the various measurement issues. Perhaps the more important result, however, is that teachers who switch schools within a district, switch districts, or exit the Texas public schools entirely do not appear more effective than those who remain in their school and quite possibly are less effective. This finding is clearest for the typical teacher who exits the Texas Public Schools. Moreover, teachers leaving the most disadvantaged schools in terms of student populations are consistently less effective than those who stay. * Hoover Institution/Stanford University, University of Texas at Dallas, and National Bureau of Economic Research; Amherst College, University of Texas at Dallas, and National Bureau of Economic Research, respectively. We thank Dan O’Brien for help with the data development and early analytical work. This research has received support from the Spencer Foundation, the Hewlett Foundation, and the Packard Humanities Institute. Do Disadvantaged Urban Schools Lose Their Best Teachers? By Eric A. Hanushek and Steven G. Rivkin Current views about the distribution of teachers across schools are largely based on observations about experience and education differences rather than differences in actual classroom effectiveness. Recent research documents substantial variation in teacher quality as measured by value added to student achievement, much of which is not captured by characteristics typically used in the hiring and salary determination processes including postgraduate schooling and experience. Consequently an understanding of the impact of teacher transitions on school quality cannot focus simply on such observed characteristics. In this paper we study differences in teacher value added among teachers who remain in the same school, school switchers, and those who exit Texas public schools in order to understand better the impact of such transitions on large urban districts. One strand of literature emphasizes the importance of community type, wealth, crime, and the other factors on the choice of jobs and presents a prima facie case that teacher quality is not distributed equitably. Boyd, Lankford, Loeb, and Wyckoff (2005) show that teacher labor markets tend to be highly localized, which complicates recruitment efforts in both urban centers and rural areas. Teachers also appear to prefer schools with higher achieving, higher income students, in addition to higher salaries (Lankford, Loeb, and Wyckoff (2002), Hanushek, Kain, and Rivkin (2004), Scafidi, Sjoquist, and Stinebrickner (2007)). Moreover, there is also evidence that teacher exit probabilities are higher for those with better alternative earning opportunities or more education (Dolton and van der Klaauw (1995, (1999)). These findings support the notion that high poverty and geographically isolated schools face myriad impediments to teacher hiring and retention, a view reinforced by administrators in rural areas and large urban districts who often bemoan both the difficulty of attracting teachers and the loss of teachers to the suburbs, private schools, and other occupations. Importantly, none of these studies provides direct evidence on classroom effectiveness, thus constituting a large void in our ability to understand the dynamics of teacher labor market. Even if teachers with better alternative earnings opportunities are more likely to quit teaching and inner city and rural schools experience higher turnover than suburban schools, the implications for policy remain unclear. Any impact on the wellbeing of students depends crucially on the actual effectiveness of leavers and of their replacements. To begin with, teacher effectiveness may not be strongly correlated with outside opportunities. Moreover, if teaching performance is a primary determinant of a teacher’s job satisfaction and desire to stay in a school, leavers come disproportionately from the lower end of the teacher quality distribution even when exiting is positively related to alternative earnings opportunities. As an empirical matter, Scafidi, Sjoquist, and Stinebrickner (2006) show that majority of exiting teachers from public schools do not move to higher paying jobs outside of teaching but instead are more likely either to exit the labor market entirely or switch to a lower paying job in a private school – facts that are consistent with the possibility that job satisfaction is an important determinant of teacher retention. We do not investigate the underlying motivation for teacher exits from given schools but instead concentrate simply on the relative effectiveness of those leaving. The central focus is understanding differences in average teacher value-added by school transition status and school characteristics for a large urban district in Texas. First, we consider how much teachers differ in effectiveness by estimating the variance of teacher value-added using a set of teacher-by-year