Social Connections and COVID19 Vaccination

This paper unpacks the effects of social networks on county-level COVID19 vaccinations in the US. We jointly assess the contemporaneous and dynamic network effects of vaccination exposure, to distinguish between network-mediated contemporaneous effects (e.g. "vaccine-hunter" Facebook groups crowd-source information about access and efficacy) and longer-term effects (e.g. vaccine exposure chips away vaccine hesitancy). Accounting for possible correlated shocks, socio-economic / spatial confounders, and pandemic-related shifters, we find positive stage-of-pandemic dependent contemporaneous friendship network effects, and null dynamic network effect, thus sharply distinguishing COVID19 vaccination from other infection-mitigating practices in terms of openness to social-learning over time.