Teacher Quality and Student Inequality ∗

Recent research using matched student-teacher data has confirmed the existence of an important role for teaching quality in producing student test score improvement in elementary and middle schools (Aaronson, Barrow, Sander (2007), Hanushek, Kain, O’Brien, Rivken (2005), Kane, Rockoff, and Staiger (2007)). This development has intensified concerns about the ability of underperforming schools to recruit and retain good teachers. One fears that the students who are already saddled with the least supportive parents, the most dangerous neighborhoods, and the most rundown schools will also be taught by the least effective teachers. However, research to this point has struggled to demonstrate convincingly the extent to which access to quality teaching is unequal. Furthermore, even if one finds that good teachers are concentrated at certain kinds of schools, policies that incentivize relocation of high quality teachers may not succeed in trimming student performance gaps across schools if the targeted schools are relatively insensitive to teacher quality. For example, some schools’ facilities may be in such a state of disrepair, or their students may be so unruly or ill-prepared, that even good teachers cannot manage to raise their performance. Thus, this paper aims to answer two questions. First, how equitably is teaching quality distributed within and across public high schools? And second, would the performance of students at underperforming schools improve substantially if they were taught by better teachers? To address these questions, we exploit administrative data from the North Carolina ∗PRELIMINARY AND INCOMPLETE. DO NOT CIRCULATE WITHOUT AUTHOR’S PERMISSION. This research is based on data from the North Carolina Education Research Data Center at Duke University. We acknowledge the North Carolina Department of Public Instruction for collecting and providing this information.