American Economic Journal: Applied Economics · 2025 · Seth Freedman、Daniel W. Sacks、Kosali Simon、Coady Wing
中文摘要
我们估计了疫苗的直接与间接有效性，并评估疫苗降低感染的外部性从接种者向外延伸的范围，这是政策决策的一项关键依据。我们的实证策略采用美国某一州近乎覆盖全体人口的微观数据，并利用12岁与11岁儿童获得新冠疫苗接种资格之间六个月的时间差来识别。疫苗接种使病例数减少80%，这是其直接效应。这种保护作用会外溢至密切接触者，在家庭层面产生约相当于直接效应四分之三的间接效应。然而，间接效应并未延伸至同学。我们的结果表明，在设计传染病政策时，疫苗保护作用的覆盖范围是需要考虑的重要因素。(JEL D62, H51, H75, I12, I18, J13)
Abstract
We estimate direct and indirect vaccine effectiveness and assess how far the infection-reducing externality extends from the vaccinated, a key input to policy decisions. Our empirical strategy uses nearly universal microdata from a single state and relies on the six-month delay between 12- and 11-year-old COVID vaccine eligibility. Vaccination reduces cases by 80 percent, the direct effect. This protection spills over to close contacts, producing a household-level indirect effect about three-fourths as large as the direct effect. However, indirect effects do not extend to schoolmates. Our results highlight vaccine reach as important to consider when designing policy for infectious disease. (JEL D62, H51, H75, I12, I18, J13)