This paper estimates the effect of nonpharmaceutical intervention policies on public health during the COVID-19 outbreak by considering a counterfactual case for Sweden. Using a synthetic control approach, I find that strict initial lockdown measures play an important role in limiting the spread of the COVID-19 infection, as the infection cases in Sweden would have been reduced by almost 75 percent had its policymakers followed stricter containment policies. As people dynamically adjust their behaviour in response to information and policies, the impact of nonpharmaceutical interventions becomes visible, with a time lag of around 5 weeks. Supplementary robustness checks and an alternative difference-in-differences framework analysis do not fundamentally alter the main conclusions. Finally, extending the analysis to excess mortality, I find that the lockdown measures would have been associated with a lower excess mortality rate in Sweden by 25 percentage points, with a steep age gradient of 29 percentage points for the most vulnerable elderly cohort. The outcome of this study can assist policymakers in laying out future guidelines to further protect public health, as well as facilitate plans for economic recovery.

中文翻译：

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量化COVID-19爆发期间非药物干预措施的影响：以瑞典为例

本文通过考虑瑞典的反事实案例，估计了非药物干预政策对COVID-19爆发期间公共卫生的影响。使用综合控制方法，我发现严格的初始锁定措施在限制COVID-19感染的蔓延中起着重要作用，因为如果瑞典的决策者遵循更严格的遏制政策，瑞典的感染病例将减少近75％。当人们根据信息和政策动态调整其行为时，非药物干预的影响变得明显，大约需要5周的时间。补充的鲁棒性检查和替代的差异差异框架分析并不能从根本上改变主要结论。最后，将分析范围扩大到超额死亡率，我发现，封锁措施将使瑞典的过高死亡率降低25个百分点，而最弱势的老年人群的年龄梯度则高达29个百分点。这项研究的结果可以帮助政策制定者制定未来的指南，以进一步保护公共卫生，并促进经济复苏计划。