This paper studies the role of product discovery in the demand for recorded music. We show that releasing a new album causes a substantial and permanent increase in sales of the artist's old albums—especially if the new release is a hit. Patterns in these “backward spillovers” suggest that they result from consumers discovering the artist upon hearing the new release. To explore the implications of consumers’ incomplete information, we estimate a simple, learning‐based model of market demand. Our results imply that the distribution of sales is substantially more skewed than it would be if consumers were more fully informed.

In this paper, we study the optimization problem of an unregulated air carrier which is given the exclusive right to satisfy demand for air travel between any pair of cities. It chooses a network of connections and a set of prices to maximize profits. Thus, both network design and prices are endogenous. We characterize the solution to this optimization problem when demands and costs are symmetric. Our main result is that, if there are economies of density in the number of individuals travelling between two directly connected cities, the optimal network is either a hub of size n − 1 or one in which every pair of cities is connected directly.

We study a model in which two carriers choose networks to connect cities and compete for customers. We show that if carriers compete aggressively (e.g., Bertrand-like behavior), one carrier operating a single hub-spoke network is an equilibrium outcome. Competing hub-spoke networks are not an equilibrium outcome, although duopoly equilibria in nonhub networks can exist. If carriers do not compete aggressively, an equilibrium with competing hub-spoke networks exists as long as the number of cities is not too small. We provide conditions under which all equilibria consist of hub-spoke networks.