We describe firm pricing when consumers search passively and follow simple reservation price rules. In stark contrast to other models in the literature, this approach yields equilib- rium price dispersion in pure strategies even when firms have the same marginal costs. In equilibrium, lower...

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...

Advertising messages compete for scarce attention. ?Junk? mail, ?spam? e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message beneÞt. Senders are motivated by proÞts. Costlier message...

We revisit the fundamental issue of market provision of variety associated with Chamberlin, Spence, and Dixit and Stiglitz when firms sell several products. Both products and firms are envisaged as di?erentiated. We propose a nested demand model where consumers decide upon a firm then which...

We consider commuting in a congested urban area. While an efficient time-varying toll may eliminate queuing, a toll may not be politically feasible. We study the benefit of a substitute: a parking fee at the workplace. An optimal time-varying parking fee is charged at zero rate when there is...

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 analyse Nash equilibrium in time of use of a congested facility. Users are risk averse with general concave utility. Queues are subject to varying degrees of random sorting, ranging from strict queue priority to a completely random queue. We define the key "no residual queue" property, which...

Limited consumer attention limits product market competition: prices are stochastically lower the more attention is paid. Ads compete to be the lowest price with other ads from the same sector and they compete for attention with ads from other sectors: equilibrium sector ad shares under free...

We introduce a framework that has known models of oligopolistic competition with differentiated products (the circle and the constant elasticity of substitution (CES)) as limit cases. This integrative approach incorporates both localized and global competition, as well as price-sensitive...

We consider a market in which a public firm competes against private firms, and ask what happens when the public firm is privatized. In the short run, privatization is harmful because all prices rise; the disciplinary role of the public firm is lost. In the long run, privatization leads to...