What is the effect of the COVID-19 pandemic on the 2020 US presidential election? Guided by a pre-analysis plan, we estimate the effect of COVID-19 cases and deaths on the change in county-level voting for Donald Trump between 2016 and 2020. To account for potential confounders, we include a large number of COVID-19-related controls as well as demographic and socioeconomic variables. Moreover, we instrument the numbers of cases and deaths with the share of workers employed in meat-processing factories to sharpen our identification strategy. We find that COVID-19 cases negatively affected Trump’s vote share. The estimated effect appears strongest in urban counties, in states without stay-at-home orders, in swing states, and in states that Trump won in 2016. A simple counterfactual analysis suggests that Trump would likely have won re-election if COVID-19 cases had been 5 percent lower. We also find some evidence that COVID-19 incidence had a positive effect on voters’ mobilization, helping Biden win the presidency.

COVID-19 大流行对 2020 年美国总统大选有何影响？在预分析计划的指导下，我们估计了 2016 年至 2020 年间 COVID-19 病例和死亡对唐纳德·特朗普县级投票变化的影响。为了考虑潜在的混杂因素，我们包括了大量的 COVID-19相关的控制以及人口和社会经济变量。此外，我们将病例数和死亡人数与肉类加工厂雇用的工人比例结合起来，以加强我们的识别策略。我们发现 COVID-19 案件对特朗普的投票份额产生了负面影响。在城市县、没有居家令的州、摇摆州以及特朗普在 2016 年获胜的州中，估计的影响似乎最强。一项简单的反事实分析表明，如果 COVID-19 病例减少 5%，特朗普可能会赢得连任。我们还发现一些证据表明，COVID-19 的发病率对选民的动员产生了积极影响，帮助拜登赢得了总统职位。