Book excerpt: The degree to which markets incorporate information is one of the most important questions facing economists today. This book provides a fascinating study of the existence and extent of information efficiency in financial markets, with a special focus on betting markets. Betting markets are selected for study because they incorporate features highly appropriate to a study of information efficiency, in particular the fact that each bet has a well-defined end point at which its value becomes certain. Using international examples, this book reviews and analyses the issue of information efficiency in both financial and betting markets. Part I is an extensive survey of the existing literature, while Part II presents a range of readings by leading academics. Insights gained from the book will interest students of financial economics, financial market analysts, mathematicians and statisticians, and all those with a special interest in finance or gambling.