Biased Beliefs in Search Markets

We study the implications of biased consumer beliefs for search market outcomes in the seminal framework due to Diamond (1971). Biased consumers base their search strategy on a belief function which specifies for any (true) distribution of utility offers in the market a possibly incorrect distribution of utility offers. If biased consumers overestimate the best offer in the market, a novel type of equilibrium may emerge in which firms make exceptionally favourable offers in order to meet biased consumers' unreasonable high expectations which then become partially self-fulfilling. Consequently, the presence of biased consumers may improve the welfare of all consumers.