Instructional time is a fundamental educational input, yet we have little causal evidence about the effect of longer school days on student achievement. This paper uses a sharp regression discontinuity design to estimate the effects of lengthening the school day for low-performing schools in Florida by exploiting an administrative cutoff for…

In this article, Ardice Hartry, Robert Fitzgerald, and Kristie Porter present results from their implementation study of a structured reading program for fourth, fifth, and sixth graders in an afterschool setting. As the authors explain, schools and districts often view an extended school day as a promising way to address the literacy needs of…