[gov3009-l] Applied Statistics Workshop: Joshua Goodman on Wed., March 7

Recent research on charter schools, summer learning loss, and international achievement suggests that instructional time is a critical input to the education production function. Using student and school-grade fixed effects models with data from Massachusetts, I find no relation between school closures and achievement but a strong relation between student absences and achievement. I then confirm these results using temporal and spatial variation in snowfall to provide better identification. Extreme snowfall induces school closures but does not affect achievement. Moderate snowfall induces student absences and does reduce achievement. Instrumental variables estimates suggest that each absence induced by bad weather reduces math achievement by 0.05 standard deviations. These results are consistent with a model of instruction in which coordination of students is the central challenge. Teachers deal well with coordinated disruptions of instructional time like school closures, but deal poorly with absences that affect different students and different times. These estimates suggest that absences are responsible for up to 20% of the achievement gap between poor and nonpoor students. They also suggest that policies designed solely to increase instructional time may not be effective.