COVID-19 vaccine and risk-taking
利用十四个月的追踪调查数据，研究发现接种COVID-19疫苗后人们会增加风险行为（如去酒吧和餐厅），这可能削弱疫苗效果，对公共卫生政策制定者有参考价值。
Abstract We assess whether the COVID-19 vaccine induces COVID-19 risky behavior (e.g., going to bars and restaurants) and thus reduces vaccine efficacy. A key empirical challenge is the endogeneity bias when comparing risk-taking by vaccination status since people choose whether to get vaccinated. To address this bias, we exploit rich survey panel data on individuals followed before and after vaccine availability over fourteen months in an event study fixed effects model with individual, time, sector, and county-by-time fixed effects and inverse propensity weights. We find evidence that vaccinated persons, regardless of the timing of vaccination, increase their risk-taking activities. The evidence is consistent with the “lulling effect”. While vaccine availability may reduce the risk of contracting COVID-19, it also contributes to further spread of the virus by incentivizing risk-taking in the short term.