Despite the fact that the average American student is absent more than two weeks out of every school year, most research on the effect of instructional time has focused not on attendance but on the length of the school day or year. Student and school fixed effects models using Massachusetts data...

We study an intensive math instruction policy that assigned low-skilled 9th graders to an algebra course that doubled instructional time, altered peer composition and emphasized problem solving skills. A regression discontinuity design shows substantial positive impacts of double-dose algebra on...

Only half of SAT-takers retake the exam, with even lower retake rates among low income and underrepresented minority (URM) students. We exploit discontinuous jumps in retake probabilities at multiples of 100, driven by left-digit bias, to estimate retaking's causal effects. Retaking...