Clearinghouse models of online pricing - such as Varian (1980), Rosenthal (1980), Narasimhan (1988), and Baye-Morgan (2001) - view a price comparison site as an "information clearing-house" where shoppers and loyals obtain price and product information to make online purchases. These models...

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)...