From A to Z: how alphabetic class labels shape educational stratification in fixed-cohort systems

Fixed-cohort systems with alphabetic class labels affect hundreds of millions of students worldwide yet remain unexamined in comparative education research. This study examines whether alphabetic class assignment generates educational stratification in Kazakhstan, where students remain in labelled classes throughout schooling. Using administrative data on 378,662 graduates from 3060 schools (2021–2023) and school fixed effects, we find that students in later-labelled classes experience worse outcomes. Moving from the first to the last alphabetically ordered class associates with a 3.8% decrease in test scores, 3.3 percentage points lower university enrolment, and 2.8 percentage points fewer scholarships – magnitudes comparable to Western tracking effects. Effects persist from ninth grade through high school. Mechanism decomposition reveals 70.6% of the variation operates through unobserved channels consistent with teacher expectations and peer dynamics. Findings demonstrate that ostensibly neutral administrative practices generate substantial stratification, with implications for educational equity worldwide.