We utilized the synthetic difference-in-difference method to estimate the impact of adopting a permitless Concealed Carry Weapons (CCW) law on rates of assaults, robberies, and homicides committed with a firearm and by other means, as well as weapons arrests, from 1981 to 2019. We stratified permitless CCW laws by whether they previously prohibited violent misdemeanants from obtaining a CCW permit or previously required live firearm training to obtain a permit prior to law adoption. Findings robust to sensitivity analyses suggest that states that lost a training requirement to obtain a CCW permit had 21 additional gun assaults per 100,000 population (SE = 5.2) (32% increase).

中文翻译：

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放松对公共平民持枪和暴力犯罪的管制：1981-2019 年的纵向分析

我们利用综合双重差分法来估计采用未经许可的隐藏携带武器 (CCW) 法对使用枪支和其他手段实施的袭击、抢劫和杀人率以及武器逮捕率的影响， 1981 年至 2019 年。我们对无需许可的《特定常规武器公约》法律进行了分层，依据是这些法律之前是否禁止暴力轻罪者获得《特定常规武器公约》许可证，或者之前是否要求在法律通过之前进行实弹枪械训练才能获得许可证。敏感性分析的结果表明，失去获得《特定常规武器公约》许可证的培训要求的州每 10 万人口会增加 21 起枪支袭击事件 (SE = 5.2)（增加 32%）。