Heterogeneous peer effects of college roommates on academic performance

TL;DR

This study investigates how college roommates influence academic performance over time, revealing that peer effects strengthen with longer cohabitation and are moderated by roommate similarity and rank.

Contribution

It introduces a novel null-model and assimilation metric to quantify peer effects in longitudinal data, highlighting the dynamic nature of roommate influence.

Findings

Roommates exhibit more similar academic performance than expected by chance.

Peer effects increase as roommates live together longer.

Similarity and rank moderate the impact of peer effects.

Abstract

Understanding how student peers influence learning outcomes is crucial for effective education management in complex social systems. The complexities of peer selection and evolving peer relationships, however, pose challenges for identifying peer effects using static observational data. Here we use both null-model and regression approaches to examine peer effects using longitudinal data from 5,272 undergraduates, where roommate assignments are plausibly random upon enrollment and roommate relationships persist until graduation. Specifically, we construct a roommate null model by randomly shuffling students among dorm rooms and introduce an assimilation metric to quantify similarities in roommate academic performance. We find significantly larger assimilation in actual data than in the roommate null model, suggesting roommate peer effects, whereby roommates have more similar performance than expected by chance alone. Moreover, assimilation exhibits an overall increasing trend over time, suggesting that peer effects become stronger the longer roommates live together. Our regression analysis further reveals the moderating role of peer heterogeneity. In particular, when roommates perform similarly, the positive relationship between a student's future performance and their roommates' average prior performance is more pronounced, and their ordinal rank in the dorm room has an independent effect. Our findings contribute to understanding the role of college roommates in influencing student academic performance.