Unpacking Treatment Effect Heterogeneity in a Large-Scale Dropout Prevention Experiment

Authors

• Thomas Dee, Stanford University and National Bureau of Economic Research
• Chloe R. Gibbs, W.E. Upjohn Institute for Employment Research and University of Notre DameFollow
• Rebecca Margolit-Chan, Cornell University
• Lillian Morrell, University of Notre Dame
• James X. Sullivan, University of Notre Dame

Upjohn Author ORCID Identifier

https://orcid.org/0000-0002-2684-053X

Series

Upjohn Institute working paper ; 26-438

DOI

10.17848/wp26-438

Issue Date

August 2026

Abstract

Timely high school completion is a critical step in successful transitions to post-secondary schooling and the labor market. This randomized controlled trial, deployed in two urban, disadvantaged school districts, tests the effectiveness of a mature and comprehensive student-support program on an unusually large scale (n=2,528). While overall effects on graduation rates are small and statistically insignificant, exploratory analyses reveal notable variation by site and over time, mirroring heterogeneity in treatment timing and program implementation. These findings highlight the challenges of scaling interventions and raise concerns about generalizing results from small-scale, single-site evaluations.

Sponsorship

University of Notre Dame Wilson Sheehan Lab for Economic Opportunities and the Abdul Latif Jameel Poverty Action Lab

Subject Areas

EDUCATION; K-12 Education; Postsecondary education; LABOR MARKET ISSUES