In 2003, Chicago launched "Double-Dose Algebra," requiring students with pretest scores below the national median to take two periods of math--algebra and supplemental coursework. In many schools, assignment to Double Dose changed the peer composition of the algebra classroom. Using school-specific instrumental variables within a…

To understand heterogeneity in the effects of double-dose algebra across schools, the authors focus on two policy implementation features and their variation across schools. The first source of variation is the degree to which schools followed the cutoff-based course assignment policy. The second source of variation is the degree to which schools…