Goodman, Joshua. National Bureau of Economic Research, Working Paper No. 20221, June 2014. This report examines the effects of moderate snow on poor student absences, which was twice as large as for non-poor students. It was also twice as large for black and Hispanic students as for white and Asian students. The author speculates that this may be caused by dependence on “forms of transportation more likely to fail during snowstorms, such as public transit or low quality cars” or to placing “less value on school attendance.” Extremely snowy days, days with 10 or more inches of snow, produce more school closures but no additional absences because students cannot be absent when a school is closed. Previous studies finding that closures had large achievement effects may have mistakenly attributed the effect of individual absences to school closures. The author concludes that teachers deal well with coordinated disruptions of instructional time but poorly with disruptions that affect different students at different times. The negative effect that absences have on achievement suggests that lengthening the school day or year will not necessarily have the desired effect of raising student performance, but that policies to improve attendance might help.