"Vaccination Uptake and Policy Intervention: An Experiment"

In this paper we want to investigate patterns of vaccination uptake in a simultaneous-move game in a small contagious network, and effectiveness of a number of different policy interventions in correcting inefficiencies. Theoretical analysis shows that, in the absence of intervention, in a complete network there are inefficient equilibria in which too few people vaccinate. Further, when the network is irregular, multiple equilibria exist and there are three possible types of inefficiencies: under-vaccination, over-vaccination, and situations in which the right number but the wrong set of agents vaccinate. We want to examine behaviour and how the rate of contagiousness of an infection affects equilibrium selection. Further, we want to investigate and compare the relative effectiveness of a number of policy interventions in getting agents out of the inefficient equilibrium. Specific mechanisms of intervention are fines for non-vaccination, subsidies for vaccination, as well as behavioural nudges highlighting positive externalities of vaccination and negative externalities of non-vaccination.