Improved consumer information about horizontal aspects of products of similar quality leads to better consumer matching but also to higher prices, so consumer surplus can go up or down, while profits rise. With enough quality asymmetry, though, the higher-quality (and hence larger) firm's price...

Unsolicited advertising messages vie for scarce attention. Junk mail, spam e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message receivers supply attention according to average message benefit, while the marginal sender determines congestion....

We study price competition in the presence of search costs and product differentiation. The limit cases of the model are the "Bertrand Paradox," the "Diamond Paradox," and Chamberlinian monopolistic competition. Market prices rise with search costs and decrease with the number of firms. Prices...