Steady-State Social Distancing and Vaccination

This paper analyzes an economic-epidemiological model of infectious disease where it is possible to become infected more than once and individual agents make endogenous choices of social distancing and vaccine adoption. Protective actions adopted by any one person reduce future risks to other people. The positive externalities associated with these behaviors provide motivation for vaccine and social-distancing subsidies, but subsidizing one protective action reduces incentives for other protective actions. A vaccine subsidy increases vaccine adoption and reduces steady-state infection prevalence; a social distancing subsidy can either increase or reduce steady-state infection prevalence. (JEL D62, D91, I12, I18)