This paper evaluates alternative strategic models of competition and market structure in online retailing, and makes comparisons with traditional retailing. Online consumers are less concerned than traditional consumers about spatial characteristics and more concerned about hidden quality...

Firms selling multiple quality-differentiated products frequently alter their product lines when a competitor enters the market. We present a model of multiproduct monopoly and duopoly using a general `upgrades` approach that yields a powerful analytical framework. We provide a simple...

We consider the optimal pricing and referral strategy of a monopoly that uses a simple consumer communication network (a chain) to spread product information. The first-best policy with fully discriminatory position-based referral fees involves standard monopoly pricing and referral fees that...

We present a general Cournot model in which each firm may sell multiple quality-differentiated products. We use an upgrades approach, working not with the actual products, but instead with upgrades from one quality to the next. The properties of single-product Cournot models carry over to the...