With few exceptions, empirical research investigating the possibility of heterogeneous benefits of class size reduction lacks a conceptual framework about specific dimensions of potential heterogeneity. In this paper we develop a model of education production that incorporates disruption and student achievement and illustrates how these underlying…

Do smaller classes boost achievement mainly by helping teachers impart specific academic skills to students with low academic achievement? Or do they do so primarily by helping teachers engage poorly behaving students? The analysis uses the grade 3 to 4 transition in San Diego Unified School District as a source of exogenous variation in class…

In Project STAR, 11,571 students in Tennessee and their teachers were randomly assigned to different classrooms within their schools from kindergarten to third grade. This paper evaluates the long-term impacts of STAR using administrative records. We obtain five results. First, kindergarten test scores are highly correlated with outcomes such as…

This paper introduces an empirical strategy to estimate dynamic treatment effects in randomized trials that provide treatment in multiple stages and in which various noncompliance problems arise such as attrition and selective transitions between treatment and control groups. Our approach is applied to the highly influential four year randomized…