This paper (1) presents a general model of online price competition, (2) shows how to structurally estimate the underlying parameters of the model when the number of competing firms is unknown or in dispute, (3) estimates these parameters based on UK data for personal digital assistants, and (4)...

We examine the equilibrium interaction between a market for price information (controlled by a gatekeeper) and the homogenous product market it serves. The gatekeeper charges fees to firms that advertise prices on its Internet site and to consumers who access the list of advertised prices....