How Would One Extra Year of High School Affect Academic Performance in University? Evidence from an Educational Policy Change

This paper uses a unique policy change in Ontario, Canada, to provide direct evidence on how reducing the length of high school would impact student performance in university. After a five‐year educational program was eliminated from Ontario high schools and replaced with a four‐year program, two graduating cohorts with different amounts of high school education simultaneously entered university. The results demonstrate that students who receive one less year of high school education perform significantly worse than their counterparts in all subjects, even after the age difference between the cohorts is accounted for.