From the Internet to networks of friendship, disease transmission, and even terrorism, the concept--and the reality--of networks has come to pervade modern society. But what exactly is a network? What different types of networks are there? Why are they interesting, and what can they tell us? In recent years, scientists from a range of fields--including mathematics, physics, computer science, sociology, and biology--have been pursuing these questions and building a new "science of networks." This book brings together for the first time a set of seminal articles representing research from across these disciplines. It is an ideal sourcebook for the key research in this fast-growing field. The book is organized into four sections, each preceded by an editors' introduction summarizing its contents and general theme. The first section sets the stage by discussing some of the historical antecedents of contemporary research in the area. From there the book moves to the empirical side of the science of networks before turning to the foundational modeling ideas that have been the focus of much subsequent activity. The book closes by taking the reader to the cutting edge of network science--the relationship between network structure and system dynamics. From network robustness to the spread of disease, this section offers a potpourri of topics on this rapidly expanding frontier of the new science.

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

With the rise of digital platforms and the natural tendency of markets involving platforms to become concentrated, competition authorities and courts are more frequently in a position to investigate and decide merger and abuse cases that involve platforms. This report provides guidance on how to define markets and on how to assess market power when dealing with two-sided platforms. DEFINITION Competition authorities and courts are well advised to uniformly use a multi-markets approach when defining markets in the context of two-sided platforms. The multi-markets approach is the more flexible instrument compared to the competing single-market approach that defines a single market for both sides of a platform, as the former naturally accounts for different substitution possibilities by the user groups on the two sides of the platform. While one might think of conditions under which a single-market approach could be feasible, the necessary conditions are so severe that it would only be applicable under rare circumstances. To fully appreciate business activities in platform markets from a competition law point of view, and to do justice to competition law’s purpose, which is to protect consumer welfare, the legal concept of a “market” should not be interpreted as requiring a price to be paid by one party to the other. It is not sufficient to consider the activities on the “unpaid side” of the platform only indirectly by way of including them in the competition law analysis of the “paid side” of the platform. Such an approach would exclude certain activities and ensuing positive or negative effects on consumer welfare altogether from the radar of competition law. Instead, competition practice should recognize straightforwardly that there can be “markets” for products offered free of charge, i.e. without monetary consideration by those who receive the product. ASSESSMENT The application of competition law often requires an assessment of market power. Using market shares as indicators of market power, in addition to all the difficulties in standard markets, raises further issues for two-sided platforms. When calculating revenue shares, the only reasonable option is to use the sum of revenues on all sides of the platform. Then, such shares should not be interpreted as market shares as they are aggregated over two interdependent markets. Large revenue shares appear to be a meaningful indicator of market power if all undertakings under consideration serve the same sides. However, they are often not meaningful if undertakings active in the relevant markets follow different business models. Given potentially strong cross-group external effects, market shares are less apt in the context of two-sided platforms to indicate market power (or the lack of it). Barriers to entry are at the core of persistent market power and, thus, the entrenchment of incumbent platforms. They deserve careful examination by competition authorities. Barriers to entry may arise due to users’ coordination failure in the presence of network effect. On two-sided platforms, users on both sides of the market have to coordinate their expectations. Barriers to entry are more likely to be present if an industry does not attract new users and if it does not undergo major technological change. Switching costs and network effects may go hand in hand: consumer switching costs sometimes depend on the number of platform users and, in this case, barriers to entry from consumer switching costs increase with platform size. Since market power is related to barriers to entry, the absence of entry attempts may be seen as an indication of market power. However, entry threats may arise from firms offering quite different services, as long as they provide a new home for users’ attention and needs.

Handbook of Industrial Organization Volume 4 highlights new advances in the field, with this new volume presenting interesting chapters. Each chapter is written by an international board of authors. Part of the renowned Handbooks in Economics series Chapters are contributed by some of the leading experts in their fields A source, reference and teaching supplement for industrial organizations or industrial economists

“A fascinating book about how platform internet companies (Amazon, Facebook, and so on) are changing the norms of economic competition.” —Fast Company Shoppers with a bargain-hunting impulse and internet access can find a universe of products at their fingertips. But is there a dark side to internet commerce? This thought-provoking exposé invites us to explore how sophisticated algorithms and data-crunching are changing the nature of market competition, and not always for the better. Introducing into the policy lexicon terms such as algorithmic collusion, behavioral discrimination, and super-platforms, Ariel Ezrachi and Maurice E. Stucke explore the resulting impact on competition, our democratic ideals, our wallets, and our well-being. “We owe the authors our deep gratitude for anticipating and explaining the consequences of living in a world in which black boxes collude and leave no trails behind. They make it clear that in a world of big data and algorithmic pricing, consumers are outgunned and antitrust laws are outdated, especially in the United States.” —Science “A convincing argument that there can be a darker side to the growth of digital commerce. The replacement of the invisible hand of competition by the digitized hand of internet commerce can give rise to anticompetitive behavior that the competition authorities are ill equipped to deal with.” —Burton G. Malkiel, Wall Street Journal “A convincing case for the need to rethink competition law to cope with algorithmic capitalism’s potential for malfeasance.” —John Naughton, The Observer

The customer base is an important value driver of software companies and a reliable prediction of its development is fundamental for investment decisions. A particularity in software markets is that an individual’s purchasing decision is often influenced by other users’ choices. Although such customer network effects are evident, their quantitative assessment remain elusive with conventional approaches. This book contributes to closing this gap by developing methods for measuring network effects and their implications for valuation in software markets. Based on the theory of complex networks the book reveals that such diffusion processes highly depend on structural properties of customer networks. Moreover, it depicts that such insights are contributions to improve the quality of valuations in software markets. But the implications of this research also comprise social and political aspects as they can be applied in order to prevent corporate failures in all network effect markets.

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.