Social distancing measures have been imposed across the United States in order to stem the spread of COVID‐19. We quantify the reduction in the doubling rate, by state, that is associated with this intervention. Using the earlier of K‐12 school closures and restaurant closures, by state, to define the start of the intervention, and considering daily confirmed cases through April 23, 2020, we find that social distancing is associated with a statistically‐significant (p < 0.01) reduction in the doubling rate for all states except for Nebraska, North Dakota, and South Dakota, when controlling for false discovery, with the doubling rate averaged across the states falling from 0.302 (0.285, 0.320) days⁻¹ to 0.010 (−0.007, 0.028) days⁻¹. However, we do not find that social distancing has made the spread subcritical. Instead, social distancing has merely stabilized the spread of the disease. We provide an illustration of our findings for each state, including estimates of the effective reproduction number, R, both with and without social distancing. We also discuss the policy implications of our findings.

中文翻译：

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社交距离仅仅稳定了美国的 COVID-19。


为了阻止 COVID-19 的传播，美国各地实施了社会疏远措施。我们按州量化了与这种干预相关的倍增率的降低。使用按州划分的 K-12 学校关闭和餐厅关闭中较早的一个来定义干预措施的开始时间，并考虑到 2020 年 4 月 23 日之前的每日确诊病例，我们发现社交距离与统计上显着的 ( p % 3C 0.01 ) 在控制错误发现时，除内布拉斯加州、北达科他州和南达科他州外的所有州的倍增率均下降，各州平均倍增率从 0.302 (0.285, 0.320) 天^-1降至 0.010 ( − 0.007, 0.028) 天⁻¹ 。然而，我们并没有发现社交距离使传播变得不那么危险。相反，社会疏远仅仅稳定了疾病的传播。我们提供了每个州的研究结果的说明，包括在有和没有社交距离的情况下有效繁殖数R的估计。我们还讨论了我们的研究结果的政策影响。