Attending a school with heterogeneous peers: The effects of school detracking and its attenuation

This paper examines the effects of high school detracking on Korean Scholastic Aptitude Test (KSAT) scores in the subjects of Korean (reading), mathematics, and English. We found that a transition to detracking reduces test scores by 0.16–0.18 of one standard deviation. Additionally, the administrative autonomy of private schools and the use of private tutoring services at home attenuate the negative effects of detracking. Our findings are in line with those in the previous literature showing a modest effect of tracking (i.e., ability sorting) in advanced countries where the autonomous school system is well organized and commercial educational services are easily accessible and a strong positive effect of tracking in developing countries where access to well-resourced private schools and private education is generally limited.