The Dynamics and Spillovers of Management Interventions: A Comment on Bianchi and Giorcelli (2022)
Bianchi and Giorcelli (2022) study the long-term and spillover e ects of a management intervention program on rm performance in the US, between 1940 and 1945. The authors nd that the Training Within Industry (TWI) program led to positive e ects which lasted for at least 10 years. Firm sales of treated rms increasedd by 5.3% in the rst year after implementation, peaking at 21.7% after 8 years, before reducing to 16% gains after a decade. The authors claim that the program generated long-lasting changes in managerial practices. Finally, the program also led to positive spillover e ects on the supply chain of treated rms. First, we reproduce the paper's main ndings. Second, we test the robustness of the results to (1) changing the main speci cation sample and (2) testing other di erence-in-di erences estimators, using the same data, provided by the authors. We nd that the results are robust to these changes. All point estimates in the study remain statistically signi cant and of similar magnitude.
While the paper's nding reproduce and replicate, challenges in reproducing results we encountered lead us to recommend improvements to journals' code policies.