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…

Discusses research (Tennessee Study of Class Size) that determined the effects of smaller class size in the earliest grades on short- and long-term pupil performance. The 4-year study assessed the performance of over 6,500 students who attended K-3 classrooms having differing numbers of students and found evidence of short- and long-term benefits…

During 1999/2000, the Saginaw, Michigan public schools implemented a reduced class size program in grades 1 and 2. At grade 1 (23 rooms), reduced-size classes were maintained at no more than 18 pupils; at grade 2 (5 rooms), the limit was 21 pupils. Comparison classes were identified to assess the impact of the program. Students in both conditions…