Before 1974, general high schools in Korea were stratified by a selective admission system.Starting from 1974, it was replaced by a leveling system in which students were randomlyassigned to a school within a district. This paper examines whether the quality of school tiesformed by senior graduates of the selective system affects contemporary outcomes of juniorgraduates randomly assigned to the same school under the leveling system. The quality ofschool ties does not strongly affect the average junior graduate’s outcomes. In contrast, itbenefits junior graduates who rank high in the outcome distribution.