Schooling and test scores: A mother-natural experiment

In the economics of education, no task has been more important or more difficult than identifying the relationship between school inputs and student performance. The literature on this topic has reached little resolution, largely owing to the endogeneity of school resources. In this paper I examine the effect of a vital but little studied component of the education production function: instructional time. To identify the impact of schooling on test scores I make use of the fact that variation in winter weather made non-trivial differences in the number of school days students received prior to taking the Maryland School Performance Assessment Program (MSPAP) exams. I find evidence that students who took exams in years with heavy snowfall performed significantly worse than their peers in the same school who took MSPAP exams in other years. I also find that performance in a subject with relatively inflexible curricula (mathematics) and students in earlier grades were most affected by snow. Both of these findings are consistent with the interpretation that education inputs in the form of instructional days improve students’ test scores.