Policy Design for COVID‐19: Worldwide Evidence on the Efficacies of Early Mask Mandates and Other Policy Interventions
利用全球数据，研究发现早期实施口罩强制令能有效降低短期感染率并提升长期效果，而其他五项政策（如封锁、旅行禁令等）效果较弱。对政策制定者应对危机有参考价值。
To understand the extent to which a policy instrument's early adoption is crucial in crisis management, we leverage unique worldwide data that record the daily evolution of policy mandate adoptions and COVID-19 infection and mortality rates. The analysis shows that the mask mandate is consistently associated with lower infection rates in the short term, and its early adoption boosts the long-term efficacy. By contrast, the other five policy instruments-domestic lockdowns, international travel bans, mass gathering bans, and restaurant and school closures-show weaker efficacy. Governments prepared for a public health crisis with stronger resilience or capacity and those with stronger collectivist cultures were quicker to adopt nationwide mask mandates. From a policy design perspective, policymakers must avoid overreacting with less effective instruments and underreacting with more effective ones during uncertain times, especially when interventions differ in efficacy and cost.