The Impact of Individual Teachers on Student Achievement: Evidence from Panel Data

Teacher quality is widely believed to be important for education, despite little evidence that teachers' credentials matter for student achievement. To accurately measure variation in achievement due to teachers' characteristics-both observable and unobservable-it is essential to identify teacher fixed effects. Unlike previous studies, I use panel data to estimate teacher fixed effects while controlling for fixed student characteristics and classroom specific variables. I find large and statistically significant differences among teachers: a one standard deviation increase in teacher quality raises reading and math test scores by approximately .20 and .24 standard deviations, respectively, on a nationally standardized scale. In addition, teaching experience has statistically significant positive effects on reading test scores, controlling for fixed teacher quality.