reviewed at a Research Roundtable Conference at Northwestern University Law School's Searle Center for Law, Regulation, and Economic Growth. We thank Henry Butler, Director of the Searle Center, for hosting the conference. We thank the participants for their helpful discussion and comments: Babette Boliek, Acknowledgments Michelle Connolly, David Gabel, Shane Greenstein, Keith Hylton, Pierre Larouche, John Lopatka, Julian Morris, William Page, Susan Perkins, William Rogerson, David Sappington, Hans-Bernd Schäfer, William Sharkey, J. Gregory Sidak, D. Daniel Sokol, James Speta, Jagannadha Pawan Tamvada, Ingo Vogelsang, and Kevin Werbach. The book draws upon material from the following publications: Spulber, Daniel F., and Christopher S. Yoo 2003. "Access to networks: Economic and con- stitutional connections," Cornell Law Review 88: 885-1024. 2005. "On the regulation of networks as complex systems: A graph theory approach," Northwestern University Law Review 99: 1687-1722. 2005. "Network regulation: The many faces of access," Journal of Competition Law and Economics 1: 635-78. 2007. "Mandating access to telecom and the Internet: The hidden side of Trinko," Columbia Law Review 107:101-82. 2008. "Rethinking broadband Internet access," Harvard Journal on Law and Tech- nology 22: 1-74. 2008. "Toward a unified theory of access to local telephone networks," Federal Communications Law Journal 61: 43-117. Yoo, Christopher S. 2005. "Beyond network neutrality," Harvard Journal of Law and Technology 19: 1-77. 2006. "Network neutrality and the economics of congestion," Georgetown Law Journal 94: 1847-1908. Introduction The purpose of this book is to examine the implications of network theory for public policy toward communications. Network theory provides a highly useful and powerful tool for modeling and understanding communications networks. Network theory opens the "black box" of networks to reveal the complexities of network architecture. Rather than working with the reduced form of the standard economic cost function, ne