This book examines the economics of an industry that has become a critical component of modern life - the electric utility industry. The public nature of electricity has affected the development of the industry, both private and public. While this book focuses on private utilities, it recognizes the potential for a resurgence of public ownership. The objective of the book is to examine factors that will affect the evolution of markets for power. Of critical importance is the role of information, which is required for making and evaluating decisions in power markets. This book demonstrates that utilities can exploit information as a source of market power, impeding the development of more competitive and efficient markets. To a large extent the source of the utilities' market power is the ability to specify computer models used in the planning, pricing and operation of markets for electricity. A number of concepts related to the use and control of information and models are developed in this book.