Advertising competes for scarce consumer attention, so more profitable advertisers send more messages to break through the others' clutter. Multiple equilibria can arise: more messages in aggregate induce more "shouting to be heard", dissipating profit. Equilibria can involve a small range of...

We analyze an oligopoly model with horizontal di¤erentiation and quality di¤erences. High quality goods are over-priced and under-produced. When the market is fairly covered, low quality products may be pro…table when their social contribution is negative, leading to too many products in...

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 describe firm pricing when consumers follow simple reservation price rules. In stark contrast to other models in the literature, this approach yields price dispersion in pure strategies even when firms have the same marginal costs. At the equilibrium, lower price firms earn higher profits....

We integrate parking in a simple manner into the basic monocentric model. In equilibrium, the city divides into three zones. Closest to the CBD are parking lots, with residential housing further out. Residents contiguous to the parking lots walk to work. Those in the last band drive to a parking...