This paper presents simple conditions for monopoly third-degree price discrimination to have negative or positive e¤ectson aggregate consumer surplus. Consumer surplus is often re-duced by discrimination, for example when total welfare (con-sumer surplus and pro…ts) falls. Surplus increases...

We present a general Cournot model in which each ¯rm may sell multiplequality-di®erentiated products. We use an upgrades approach, working not with theactual products, but instead with upgrades from one quality to the next. The prop-erties of single-product Cournot models carry over to the...

This paper analyses how competition over rebates for customer loyalty across product lines affects firms` pricing and consumers generally. If buyers incur firm specific costs or have shop specific tastes then competitive loyalty discounts lower consumer surplus overall and raise profits - the...

This paper evaluates alternative strategic models of competition and market structure inonline retailing, and makes comparisons with traditional retailing. Online consumers areless concerned than traditional consumers about spatial characteristics and moreconcerned about hidden quality...