We assessed racial disparities in policing in the United States by compiling and analysing a dataset detailing nearly 100 million traffic stops conducted across the country. We found that black drivers were less likely to be stopped after sunset, when a 'veil of darkness' masks one's race, suggesting bias in stop decisions. Furthermore, by examining the rate at which stopped drivers were searched and the likelihood that searches turned up contraband, we found evidence that the bar for searching black and Hispanic drivers was lower than that for searching white drivers. Finally, we found that legalization of recreational marijuana reduced the number of searches of white, black and Hispanic drivers-but the bar for searching black and Hispanic drivers was still lower than that for white drivers post-legalization. Our results indicate that police stops and search decisions suffer from persistent racial bias and point to the value of policy interventions to mitigate these disparities.

中文翻译：

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在美国各地对警察的种族差异进行了大规模分析。

我们通过汇编和分析详细描述了全国近1亿个交通站点的数据集，评估了美国在警务方面的种族差异。我们发现，当“黑暗的面纱”遮盖了自己的比赛时，黑人驾驶员不太可能在日落之后被挡住，这表明在停车决策方面存在偏见。此外，通过检查被搜索的停车司机的比率和违禁品搜索的可能性，我们发现了证据，搜索黑人和西班牙裔司机的门槛低于白人司机。最后，我们发现休闲大麻的合法化减少了白人，黑人和西班牙裔驾驶员的搜索数量，但合法化后黑人和西班牙裔驾驶员的搜索标准仍然低于白人驾驶员。