Until recently, the most widely available proxy measures for teacher quality have been teacher credentials, and studies using these proxies reveal that classrooms with higher concentrations of minority, poor, and low-achieving students appear to be taught by lower quality teachers. While the use of credentials and years of experience as proxies for teacher effectiveness have been helpful in shedding light on some aspects of the teacher distribution dilemma, the approach also has been limiting, in that credentials alone do not necessarily fully or even accurately capture a teacher’s ability to increase student achievement.

This study addresses whether teacher effectiveness as defined by teacher value added is equitably distributed across different student subgroups, classrooms, schools, and districts in North Carolina. We compute value added measures for about 9,000 individual teachers using roster-matched data from all fifth through eighth grade reading and math teachers from the 2007-2008 through 2009-2010 school year.  

Although we detect some regions with higher value added than other regions, we find that geography does not fully determine student access to more effective teachers. School districts with higher-than-average concentrations of more effective teachers are present in nearly every part of North Carolina. We find numerous instances of districts with high concentrations of high value-added teachers that are geographically adjacent to districts with low concentrations of high value-added teachers.

We find virtually no difference in the teacher effectiveness scores between black and white students and poor and non-poor students. Classrooms with students who were higher achievers in the previous year, however, tend to be assigned more effective teachers, a tendency that is especially strong in high-poverty schools. Low poverty schools, on the other hand, tend to assign more effective teachers to the lowest achieving students, at least in math. In high minority schools, high achieving blacks have greater access to more effective math teachers than low achieving blacks. In low minority schools, however, this pattern is reversed. High achieving blacks in low minority schools have lower access to more effective math teachers than low achieving blacks in low minority schools.

We conclude our study with a discussion of the implications of our findings for research on the distribution of teacher effectiveness and for policy on teacher hiring and school practices of how teachers are assigned to classrooms.