Unintended Consequences of Best Intentions: Examining Spillover Effects in Targeted Supplementary Education Interventions

This study examines spillover effects of targeted educational interventions through a field experiment in 130 rural Chinese boarding schools, comparing computer-assisted learning (CAL) and traditional workbooks. Results reveal significant negative spillovers of workbook interventions on nontarget students’ performance, particularly affecting those closely connected to targeted students. Effects intensify with increased exposure and peer interaction. The key mechanism appears motivational: Observing peers receiving supplementary workbook resources in class reduces students’ confidence in the value of their academic efforts for future careers. CAL interventions, conducted outside classrooms, show no such spillovers, highlighting the importance of considering unintended consequences in competitive, resource-limited environments.