This article examines the relationship between preschool quality and children's early development in a sample of over 7900 children enrolled in 578 preschools in rural Indonesia. Quality was measured by: (1) classroom observations using the Early Childhood Environment Rating Scale-Revised (ECERS-R); (2) teacher characteristics; and (3) structural…

Researchers have become increasingly interested in programs' main and interaction effects of two variables (A and B, e.g., two treatment variables or one treatment variable and one moderator) on outcomes. A challenge for estimating main and interaction effects is to eliminate selection bias across A-by-B groups. I introduce Rubin's causal model to…