In many markets, user benefits depend on participation and usage decisions of other users giving rise to network effects. Intermediaries manage these network effects and thus act as platforms that bring users together. This paper reviews key findings from the literature on network effects and...

This paper provides a novel rationale for the regulation of market size when heterogeneous firms compete. A regulator seeks to maximize total welfare by choosing the number of firms allowed to enter the market, e.g. by issuing a certain number of licenses. Opening up the market for more firms...

How should firms optimally choose prices and promotional strategies and how should they position their products when consumers are "relative thinkers"? We provide answers in a model that extends the seminal contributions of Varian (1980) and Narasimhan (1988) and derive both managerial...

This paper examines retail grocery price levels with a very large (unbalanced) panel of stores that operate in well-defined local markets. We explain price variation across grocery retailers by the concentration of wholesalers and retailers, and the market share of hypermarkets (and control for...

For many products, platforms enable sellers to transact with buyers. We show that the competitive conditions among sellers shape the market structure in platform industries. If product market competition is tough, sellers avoid competitors by joining different platforms. This allows platforms to...

This paper analyses a two-sided market in which two platforms compete against each other. One side, the advertisers, exerts a negative externality on the ther side, the users. It is shown that if platforms can charge advertisers only, a higher degree of competition for users can lead to higher...

Two-sided platform firms serve distinct customer groups that are connected through interdependent demand, and include major businesses such as the media industry, banking, and the software industry. A well known result of tax incidence is that consumers of a more heavily taxed good pay a higher...

We incorporate a search-theoretic model of imperfect competition into a standard model of asymmetric information with unrestricted contracts. We characterize the unique equilibrium, and use our characterization to explore the interaction between adverse selection, screening, and imperfect...

This paper studies the disposal costs' effect on consumer surplus and firms' profits. The costlier disposal, the less is disposed of, firms' competition for market shares increases, thereby benefiting consumers. Yet firms decrease their production to mitigate costs, affecting consumer surplus...