Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper uses data from a randomized evaluation of Head Start to answer two questions: (i) How much do short-run causal effects vary across Head Start centers? and (ii) Do observed inputs explain this variation? I find that the cross-center standard deviation of cognitive effects is 0.18 test score standard deviations, which is larger than typical estimates of variation in teacher or school effectiveness. Centers offering full-day service and home visiting are more effective, while centers that draw more children from center-based preschool have smaller effects. Other key inputs, including the High/Scope curriculum, teacher education, and class size are not correlated with Head Start effectiveness. (JEL H75, I21, I28, J13, J24)