We present new estimates of the importance of teachers in early grades for later grade outcomes, but unlike the existing literature that examines teacher "fade-out," we directly compare the contribution of early-grade teachers to later year outcomes against the contributions of later year teachers to the same later year outcomes. Where…

We apply "value-added" models to estimate the effects of teachers on an outcome they cannot plausibly affect: student height. When fitting the relatively simple models that are widely used in educational practice to New York City data, we find the standard deviation of teacher effects on height is nearly as large as that for math and…

There is growing interest among researchers, policy makers, and practitioners in identifying teachers who are skilled at improving student outcomes beyond test scores. However, questions remain about the validity of these teacher effect estimates. Leveraging the random assignment of teachers to classes, I find that teachers have causal effects on…

Estimates of teacher "value-added" suggest teachers vary substantially in their ability to promote student learning. Prompted by this finding, many states and school districts have adopted value-added measures as indicators of teacher job performance. In this paper, we conduct a new test of the validity of value-added models. Using…

Evidence that teachers' short-term instructional effects persist over time and predict substantial long-run impacts on students' lives provides much of the impetus for a wide range of educational reforms focused on identifying and responding to differences in teachers' value-added to student learning. However, relatively little research has…

The growing availability of data linking students to classroom teachers has made it possible to estimate the contribution teachers make to student achievement. While there is a growing consensus that teacher quality is important and current evaluation systems are inadequate, many have expressed concerns over the use of value-added measures (VAMs)…