In markets with network effects, users must form expectations about the total number of users who join a given platform. In this paper, we distinguish two ways in which rational expectations can be formed, which correspond to two different types of users-sophisticated and unsophisticated. Only sophisticated users adjust their expectations in response to platforms' price changes. We study the effect of the fraction of sophisticated users on platform profits. A monopoly platform's profits are always increasing in the fraction of sophisticated users. The profits of competing platforms in a market of fixed size are decreasing in the fraction of sophisticated users. When market expansion is introduced, the fraction of sophisticated users that maximizes competing platforms' profits may be positive and is strictly lower than 1. We also investigate the possibility of platforms investing in "educating" unsophisticated users. In a competitive environment, such education is a public good among platforms and therefore the equilibrium level is lower than the one that would maximize joint industry profits.

Are all film stars linked to Kevin Bacon? Why do the stock markets rise and fall sharply on the strength of a vague rumour? How does gossip spread so quickly? Are we all related through six degrees of separation? There is a growing awareness of the complex networks that pervade modern society. We see them in the rapid growth of the internet, the ease of global communication, the swift spread of news and information, and in the way epidemics and financial crises develop with startling speed and intensity. This introductory book on the new science of networks takes an interdisciplinary approach, using economics, sociology, computing, information science and applied mathematics to address fundamental questions about the links that connect us, and the ways that our decisions can have consequences for others.

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 first book on platforms that concisely incorporates path-breaking insights in economics over the last twenty years.

A number of technology products display positive network effects, and are used in variable quantities by heterogeneous customers. Examples include operating systems, infrastructure and back-end software, web services and networking equipment. This paper studies optimal nonlinear pricing for such products, under incomplete information, and with the threat of competitive entry. Both homogeneous and heterogeneous network effects are modeled. Conditions under which a fulfilled-expectations contract exists and is unique are established. While network effects generally raise prices, it is shown that accompanying changes in consumption depend on the nature of the network effects - in some cases, it is optimal for the monopolist to induce no changes in usage across customers, while in others cases, network effects raise the usage of all market participants. Optimal pricing is shown to include quantity discounts that increase with usage, and may also involve a nonlinear two-part tariff. These results highlight the impact of network effects on trade-offs between price discrimination and value creation, and have important managerial implications for pricing policy in technology markets. The need to deter competitive entry generally lowers profits for the monopolist, and increases customer surplus. When network effects are homogeneous across customers, the resulting entry-deterring monopoly contract is a fixed fee and results in the socially optimal outcome. However, when the magnitude of heterogeneous network effects is relatively high, there are no changes in total surplus induced by the entry threat, and the price changes merely cause a transfer of value from the seller to its customers. The presence of network effects, and of a credible entry threat, are also shown to increase distributional efficiency by reducing the disparity in relative value captured by different customer types. Regulatory and policy implications of these results are discussed.

A number of technology products display positive network effects, and are used invariable quantities by heterogeneous customers. Examples include operating systems, infrastructureand back-end software, web services and networking equipment. This paper studies optimalnonlinear pricing for such products, under incomplete information, and with the threat of competitiveentry. Both homogeneous and heterogeneous network effects are modeled. Conditions underwhich a fulfilled-expectations contract exists and is unique are established. While network effectsgenerally raise price, it is shown that accompanying changes in consumption depend on the natureof the network effects - in some cases, it is optimal for the monopolist to induce no changes in usageacross customers, while in others cases, network effects raise the usage of all market participants.Optimal pricing is shown to include quantity discounts that increase with usage, and may also involvea nonlinear two-part tariff. These results highlight the impact of network effects on trade-offsbetween price discrimination and value creation, and have important managerial implications forpricing policy in technology markets.The need to deter competitive entry generally lowers profits for the monopolist, and increasescustomer surplus. When network effects are homogeneous across customers, the resulting entry-deterringmonopoly contract is a fixed fee and results in the socially optimal outcome. However,when the magnitude of heterogeneous network effects is relatively high, there are no changes intotal surplus induced by the entry threat, and the price changes merely cause a transfer of valuefrom the seller to its customers. The presence of network effects, and of a credible entry threat, arealso shown to increase distributional efficiency by reducing the disparity in relative value capturedby different customer types. Regulatory and policy implications of these results are discussed.