Preferences and Covid-19 vaccination intentions

We set up an original vaccination demand model inspired from prospect theory to explain Covid-19 vaccination intentions among French adults. Our extension accounts for patience and valuation of the vaccination as a common good in individual preferences. This framework can explain why over 40% of the French population intended to reject the Covid-19 vaccination at the end of 2020. The model explains differences in vaccination intentions across population subgroups and, most notably, accounts for heterogeneity in vaccination behaviors among younger and older individuals that neither expected utility nor rank-dependent utility can offer. We calibrate the model based on an original survey carried out on a representative sample of the adult French population in November 2020 and allowing to identify curvatures of the value function, the discount rates and the willingness to cooperate. Out-of-sample analysis shows that this model can also predict the evolution of the vaccination intentions between November 2020 and March 2021. Finally, the model suggests that the international differences in the vaccination intentions are closely related to the vaccine-related valuation of the collective immunity.