Mandatory seatbelt laws and traffic fatalities: A reassessment
更新了Cohen和Einav（2003）关于强制安全带法效果的研究，使用1983-2019年数据和新估计方法，发现主要安全带法使车内人员死亡减少5-9%，而次要安全带法效果较小且不稳定。
Abstract Using data from the Fatality Analysis Reporting System for the period 1983–1997, Cohen and Einav ( Review of Economics and Statistics 2003; 85[4]: 828–843) found that mandatory seatbelt laws were associated with a 4–6% reduction in traffic fatalities among motor vehicle occupants. After successfully replicating their two‐way fixed effects estimates, we (1) add 22 years of data (1998–2019) to capture additional seatbelt policy variation and observe a longer post‐treatment period, (2) employ the interaction‐weighted estimator proposed by Sun and Abraham (2021) to address potential bias due to heterogeneous and dynamic treatment effects, and (3) estimate event‐study models to investigate pre‐treatment trends and explore lagged post‐treatment effects. Consistent with Cohen and Einav (2003), our updated estimates show that primary seatbelt laws are associated with a 5 to 9% reduction in fatalities among motor vehicle occupants. Estimated effects of secondary seatbelt laws are smaller in magnitude and sensitive to model choice.