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.

• Addresses topics of current public interest (social networks, the Web, the complex behavior of markets, epidemics, phenomena surrounding popularity and 'social contagion') • Has been class-tested as a textbook in a large, interdisciplinary course taken by beginning undergraduates from many different disciplines at Cornell University • Combines perspectives from economics, sociology, computing and information science, and applied mathematics

### Contents

1. Overview; Part I. Graph Theory and Social Networks: 2. Graphs; 3. Strong and weak ties; 4. Networks in their surrounding contexts; 5. Positive and negative relationships; Part II. Game Theory: 6. Games; 7. Evolutionary game theory; 8. Modeling network traffic using game theory; 9. Auctions; Part III. Markets and Strategic Interaction in Networks: 10. Matching markets; 11. Network models of markets with intermediaries; 12. Bargaining and power in networks; Part IV. Information Networks and the World Wide Web: 13. The structure of the Web; 14. Link analysis and Web search; 15. Sponsored search markets; Part V. Network Dynamics: Population Models: 16. Information cascades; 17. Network effects; 18. Power laws and rich-get-richer phenomena; Part VI. Network Dynamics: Structural Models: 19. Cascading behavior in networks; 20. The small-world phenomenon; 21. Epidemics; Part VII. Institutions and Aggregate Behavior: 22. Markets and information; 23. Voting; 24. Property.

### Reviews

'The first college-level text on network science, it should be a big hit for students in economics and business.' Stan Wasserman, Indiana University

'In this remarkable book, David Easley and Jon Kleinberg bring all the tools of computer science, economics, and sociology to bear on one of the great scientific challenges of our time: understanding the structure, function, and dynamics of networks in society. Clearly written and covering an impressive range of topics, Networks, Crowds, and Markets is the ideal starting point for any student aspiring to learn the fundamentals of the emerging field of network science.' Duncan Watts, author of Six Degrees: The Science of a Connected Age

'The field of information networks is an emerging discipline of immense importance that combines graph theory, probability and statistics, microeconomics and facets of the social sciences. Easley and Kleinberg present a panoramic view of this field, from basic graph theory all the way to the state of the art in research.' Prabhakar Raghavan, Head of Yahoo! Labs

'Networks are everywhere, in our social lives, in our economic relations, and in nature; they are now finally arriving to our classrooms. Easley and Kleinberg have written a masterful introduction to networks. This book successfully combines the game theoretic and algorithmic approaches to the study of social, economic and communication networks. It is lively, interesting, readable and accessible. It is a pleasure to teach using this book and never a dull moment for the students.' Daron Acemoglu, Charles P. Kindleberger Professor of Applied Economics, Massachusetts Institute of Technology

'David Easley and Jon Kleinberg have given us a totally new kind of basic economics text, where students learn how to analyze social networks and crowds as well as games and markets. This book covers a remarkable range of topics and offers a broad new vision of what economics can be about.' Roger Myerson, Glen A. Lloyd Distinguished Service Professor of Economics at the University of Chicago and winner of the 2007 Nobel Prize in Economics

'In my three decades plus of teaching, I cannot recall an urge to teach a new undergraduate course like the one I felt upon leafing through this wonderful introduction to everything that is new and important and intellectually challenging in our world.' Christos Papadimitriou, C. Lester Hogan Professor of EECS, University of California, Berkeley

'The elegant explanations in this book allow readers to rapidly gain a deep understanding of how networks work. Without resorting to either advanced math or even a bit of hand-waving, Easley and Kleinberg take us through the essential concepts and intriguing real-world applications.' Lada Adamic, University of Michigan

'This important and inspiring book must not be missing from the computer scientist's bookshelf in the 21st century …' Dr Jochen L. Leidner

'Far from being a terse, technical analysis, this is an elegant and engaging examination of the subject.' The Times Higher Education Supplement

'Networks, Crowds, and Markets offers students an excellent opportunity to relate enduring conceptual material, taught in numerous traditional courses, to their fast-paced and ever changing world. Typically, textbooks have not often done so. This work serves, therefore, not only as motivation for students to appreciate the beauty of the abstract, but also as a model for what textbooks might become in the near future. … Individual instructors will bring their own interests to this lively, well-written text with interesting graphic support and then tailor it to make a course that they are comfortable teaching and one that really comes alive for students.' Mathematical Reviews

'This text offers an integrated, but not superficial, introduction to … new mathematical concepts and their application across a range of social problems … an ideal text for introductory classes. It also holds great promise for people with a strong background in another field who wish to understand some of the key questions addressed by the social sciences.' H. Van Dyke Parunak, reviews.com

'This very interesting and detailed book manages to expose the wide-ranging applications of graph and network theory in a variety of areas such as game theory, auctions, web searches, horse-betting, voting, crowd behavior, trade markets and the spread of diseases. Throughout the book all necessary mathematical background is outlined in an easy to understand way, including the most interesting and curious aspects of the theory such as the Braess paradox, prisoner's dilemma and Arrow's impossibility theorem. The book concludes with a useful index and a detailed bibliography.' Zentralblatt MATH

'Easley, an economist, and Kleinberg, a computer scientist, accomplish the difficult task of making the subject available to students from basically any field without being superficial. Their text was designed as transdisciplinary from the start and will be specifically interesting to physics students who pursue an interdisciplinary career geared toward the social science and econophysics.' Physics Today