Debates about grade retention weigh the academic benefits of remediation against its social and psychological costs. Louisiana adopted a retention policy aimed at capturing these benefits while mitigating the harm. It used test score thresholds to distinguish between retention in grade 8, promotion to grade 9, and a grade "8.5" where…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…