Pulling Back the Curtain: The Relationship Between Teacher Quality and Students' Educational Outcomes.

摘要

Research over the past thirty years has repeatedly shown that the quality of a teacher is the most important schooling factor impacting student achievement, and educational policy, in turn, has reflected this assessment, both by allocating substantial resources to improving and by assessing teacher quality. Yet in spite of this broad consensus, we have yet to identify which proxies of teacher quality best predict desired outcomes. Moreover, though there is a growing recognition that the effects of teacher quality may emerge slowly or be visible only with time, little attention has been paid to students' long-term outcomes, such as postsecondary degree attainment. Therefore, in order to gain a better sense of how different indicators of teacher quality represent and impact students' educational success, this study examines the relationship between two dominant measures of teacher quality, teacher qualification and teacher effectiveness, in terms of their influence on students' short-term academic growth and long-term educational success (measured by completion of a college degree). Since students are exposed to teachers of varying quality over the course of their schooling -- and since achievement is closely related to that cumulative exposure -- this study computes cumulative teacher quality indices that are able to more precisely estimate the impact of teacher quality. Considering how these common measures of teacher quality are already being incorporated into various teacher policies, including teacher salary and evaluation, this study will help develop more coherent and complementary policies regarding teacher quality.