Price Dispersion: An Evolutionary Approach

In many markets it is possible to find rival sellers charging different prices for the same good. Earlier research has explained this phenomenon by demonstrating the existence of dispersed price equilibria when consumers must make use of costly search to discover prices. Taking as a starting point the model of Burdett and Judd (Econometrica, 1983), this paper, extending evolutionary techniques to a game with non-linear payoffs and a continuum of strategies, re-examines the question of price dispersion from an evolutionary, disequilibrium perspective. That is, firms and consumers adjust behaviour adaptively in response to current market conditions. We find that dispersed price equilibria are unstable when consumers use a fixed sample size search rule but may be stable when a reservation price rule is used.

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