Monopoly pricing with negative network effects: The case of vaccines

We study the market for vaccinations considering income heterogeneity on the demand side and monopoly power on the supply side. A monopolist has an incentive to exploit the external effect of vaccinations and leave the poor susceptible in order to increase the willingness to pay the rich. Even the possibility of price discrimination does not remove this incentive. We demonstrate that the weaknesses of standard policy measures are mitigated when income heterogeneity is taken into account. This offers an efficiency based rationale for distribution oriented national or international public health interventions.