We model a two-sided market with heterogeneous customers and two heterogeneous network effects. In our model, customers on each market side care differently about both the number and the type of customers on the other side. Examples of two-sided markets are online platforms or daily newspapers. In the latter case, for instance, readership demand depends on the amount and the type of advertisements. Also, advertising demand depends on the number of readers and the distribution of readers across demographic groups. There are feedback loops because advertising demand depends on the numbers of readers, which again depends on the amount of advertising, and so on. Due to the difficulty in dealing with such feedback loops when publishers set prices on both sides of the market, most of the literature has avoided models with Bertrand competition on both sides or has resorted to simplifying assumptions such as linear demands or the presence of only one network effect. We address this issue by first presenting intuitive sufficient conditions for demand on each side to be unique given prices on both sides. We then derive sufficient conditions for the existence and uniqueness of an equilibrium in prices. For merger analysis, or any other policy simulation in the context of competition policy, it is important that equilibria exist and are unique. Otherwise, one cannot predict prices or welfare effects after a merger or a policy change. The conditions are related to the own- and cross-price effects, as well as the strength of the own and cross network effects. We show that most functional forms used in empirical work, such as logit type demand functions, tend to satisfy these conditions for realistic values of the respective parameters. Finally, using data on the Dutch daily newspaper industry, we estimate a flexible model of demand which satisfies the above conditions and evaluate the effects of a hypothetical merger and study the effects of a shrinking market for offline newspapers.

We model duopoly competition between two platforms. They operate in a two-sided market where agents are heterogeneous on both sides of the market and are allowed to multihome. Network effects are captured within a vertical differentiation framework. Under single-homing there exists an interior equilibrium where networks exhibit asymmetric sizes and both firms enjoy positive profits. When all agents are allowed to patronize the two platforms, we show that in equilibrium multi-homing takes place on one side of the market only. Moreover, the only equilibrium exhibiting positive profits for both platforms replicates the collusive outcome.

Digital platforms controlled by Alibaba, Alphabet, Amazon, Facebook, Netflix, Tencent and Uber have transformed not only the ways we do business, but also the very nature of people's everyday lives. It is of vital importance that we understand the economic principles governing how these platforms operate. This book explains the driving forces behind any platform business with a focus on network effects. The authors use short case studies and real-world applications to explain key concepts such as how platforms manage network effects and which price and non-price strategies they choose. This self-contained text is the first to offer a systematic and formalized account of what platforms are and how they operate, concisely incorporating path-breaking insights in economics over the last twenty years.

Determinants of firm and market organization; Analysis of market behavior; Empirical methods and results; International issues and comparision; government intervention in the Marketplace.

The chapter has 9 sections, covering the theory of two-sided markets and related empirical work. Section 1 introduces the reader to the literature. Section 2 covers the case of markets dominated by a single monopolistic firm. Section 3 discusses the theoretical literature on competition for the market, focusing on pricing strategies that firms may follow to prevent entry. Section 4 discusses pricing in markets in which multiple platforms are active and serve both sides. Section 5 presents alternative models of platform competition. Section 6 discusses richer matching protocols whereby platforms price-discriminate by granting access only to a subset of the participating agents from the other side and discusses the related literature on matching design. Section 7 discusses identification in empirical work. Section 8 discusses estimation in empirical work. Finally, Section 9 concludes.

This paper sets out the basic economics of network effects and two-sided or multi-sided markets as relevant to antitrust and regulation. Network effects, and the related concept of two- (or multi-) sided markets, are playing an increasing role in antitrust/competition law in the communications sector, computer hardware and software, Computer Ticketing Services (CRS), Automated Teller Machines (ATMs) and credit card schemes sectors to name a few; and also in the evaluation of mergers, industry standards, market structure and competitive behaviour. The discussion begins by defining network effects and the way they alter the economics of market structure, competitive behaviour and pricing. The theory is then applied to concerns over the adoption of industry and product standards, mergers in the communications sector, and the pricing of mobile services. This is followed by an introduction to the theory of two-sided markets. This covers situations where network effects affect consumers in different groups or sides of the market brought together by a third party, such as credit card schemes. The theory of two-sided markets is developed and then applied to some features of credit card schemes. This paper is a module for the Kings College, University of London Postgraduate Diploma/Masters in Economics in Competition Law, 2006/2007.

Proceedings - International Academic Conference on Management, Economics and Marketing in Vienna 2015