The belief that additional time allows children to become more ready for school has affected public policy and individual practices. Prior studies estimated either associations between school entry age and academic growth or causal effects on achievement measured at one or two points. This article contributes novel causal evidence for the impacts…

In the United States, when a child turns five years of age, he or she is eligible to enroll and attend five-year old kindergarten. Parents and caregivers are often tasked with making the decision on whether or not to enroll their child when eligible to attend kindergarten or if the child should be held back another year (redshirted) and attend…