We characterize the equilibrium behavior in a broad class of competition models in which the competing firms' market shares are given by an attraction model, and the aggregate sales in the industry depend on the aggregate attraction value according to a general function. Each firm's revenues and...

This paper develops an econometric model of industry dynamics for concentrated markets that can be estimated very quickly from market-level panel data on the number of producers and consumers using a nested fixed-point algorithm. We show that the model has an essentially unique symmetric...

This paper develops an econometric model of firm entry, competition, and exit in oligopolistic markets. The model has an essentially unique symmetric Markov-perfect equilibrium, which can be computed very quickly. We show that its primitives are identified from market-level data on the number of...

Problem Definition: Thanks to the ubiquity of social media and the new business model of live-streaming e-commerce, online retailing has recently embraced increasing interactions among customers. Such interactions give rise to strong network effects, i.e., customers are attracted to purchase the...