TY  - RPRT
        AU  - Dee, Thomas S.
AU  - Gibbs, Chloe
AU  - Margolit-Chan, Rebecca
AU  - Morrell, Lillian
AU  - Sullivan, James
        TI  - Unpacking Treatment Effect Heterogeneity in a Large-Scale Dropout-Prevention Experiment
        PY  - 2026/Aug/
        PB  - Institute of Labor Economics (IZA)
        CY  - Bonn
        T2  - IZA Discussion Paper
        IS  - 18840
        UR  - https://www.iza.org/publications/dp18840
        AB  - 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.
        KW  - graduation
KW  - dropout
        ER  -