This article considers the problem of "supply-and-demand" analysis on a cross section of oligopoly markets with differentiated products. The primary methodology is to assume that demand can be described by a discrete-choice model and that prices are endogenously determined by price-setting...

In theory, free entry can lead to social inefficiency. We study the radio industry in a first attempt to quantify this inefficiency. Using cross-sectional data on advertising prices, the number of stations, and radio listening, we estimate the parameters of listeners' decisions and of firms'...