Author: Taehoon Kim(Kyung Hee University)

 This study analyzes the effect of school starting age on academic achievement from fourth grade to 12th grade, and how the effects change as students advance into higher grades. Since the actual school starting age is determined by an endogenous choice of the parents, such as early entry or postponement of entering school, we estimate the causal effect of school starting age on academic achievement using the mandatory school starting age determined by the school-entry cutoff date, and the date of birth as an instrument for the actual school starting age. The IV estimation results show that older students at school entry have higher test scores in Korean, math, and English in elementary and middle schools. The positive effects are observed even in high school. This study suggests that systems and policies are needed to help younger students learn and adapt to school.