Although existing research suggests that students benefit on a range of outcomes when they enroll in early algebra classes, policy efforts that accelerate algebra enrollment for large numbers of students often have negative effects. Explanations for this apparent contradiction often emphasize the potential role of teacher and peer effects, which…

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…