Vax Populi: The Social Costs of Online Vaccine Skepticism
CESifo, Munich, 2022
CESifo Working Paper No. 10184
This paper quantifies the impact of online vaccine skepticism on pediatric vaccine uptake and health outcomes. We propose a novel methodology that combines Natural Language Processing and an instrumental variable strategy that leverages the intransitivity of the social network’s connections. By matching the universe of Italian vaccine-related tweets for 2013-2018 with vaccine coverage and preventable hospitalizations at the municipality level, we find that a 10pp increase in anti-vaccine sentiment causes i) a 0.43pp decrease in coverage of the Measles-Mumps-Rubella vaccine, ii) additional 2.1 hospitalizations among vulnerable populations per 100,000 residents, and iii) an 11% increase in the relevant healthcare expenses, equivalent to 7,311 euros. Drawing on the results of a simulated model, we further show the importance of targeted interventions to counter misinformation and improve vaccine uptake.
Economics of Digitization