We use administrative data on North Carolina public schools to document the tendency for more highly qualified teachers to be matched with more advantaged students, and we measure the bias this pattern generates in estimates of the impacts of various teacher qualifications on student achievement. One of the strategies we use to minimize this bias…

Although many factors combine to make a successful school, most people agree that quality teachers and school principals are among the most important requirements for success, especially when success is defined by the ability of the school to raise the achievement of its students. The central question for this study is how the quality of the…