A Dynamic Model of Bertrand Competition with Entry

This paper analyzes a simple, repeated game of simultaneous entry and pricing. We report a surprising property of the symmetric equilibrium solution: If the number of potential competitors is increased above two, the market breaks down with higher probability, and the competitive outcome becomes less likely. More potential competition lowers welfare - another Bertrand paradox. The model can also be applied to auctions to explore whether a revenue maximizing auctioneer should restrict the number of bidders if bidder participation is costly.