Non-Reservation Price Equilibria and Search Without Priors

We analyse a model of oligopolistic competition in which consumers search without priors. Consumers do not have prior beliefs about the distribution of prices charged by firms and thus try to use a robust search procedure. We show that the optimal stopping rule is stochastic and that for any distribution of search costs there is a unique market equilibrium which is characterised by price dispersion. Although listed prices approach the monopoly price as the number of firms increases, the effective price paid by consumers does not depend on the number of firms.