In randomized control trials (RCTs) in the education field, the complier average causal effect (CACE) parameter is often of policy interest, because it pertains to intervention effects for students who receive a meaningful dose of treatment services. This article uses a causal inference and instrumental variables framework to examine the…

This paper examines issues related to the statistical power of impact estimates for experimental evaluations of education programs. The focus is on "group-based" experimental designs, because many studies of education programs involve random assignment at the group level (for example, at the school or classroom level) rather than at the student…