Book excerpt: This book brings satisfying definition and clarity to this field at last. Exploring the substantive differences between competition law and sector-specific regulation after the methodological integration, it presents the first detailed analysis of the many hundreds of notifications and Commission letters generated under the Article 7 procedure, identifying the most relevant cases dealing with market definition, market power, and remedies. It compares these decisions with relevant competition law cases and highlights elements with a bearing on sector-specific regulation. It also offers hugely valuable guidance through the vast amount of documents in the Commission’s CIRCA database. Topics and issues raised include the following: definition of product markets; delineation of geographic markets (including sub-national); different practices in relation to assessing single market power and collective market power; and competition problems such as refusal to deal, margin squeeze, non-price discrimination, and excessive pricing. There can be little doubt that this is the new reference point for researchers and practitioners in this domain. By systematically categorizing the concepts and legal criteria and building a solid theoretical framework on the intersection of competition law and sector-specific regulation, the author has created a resource that is sure to be welcomed by all those involved in regulation of electronic communications markets and network industries in general: academic scholars, telecommunications regulators at the EU and Member State levels, competition authorities, law firms specializing in IT/communications law, practitioners in IT and telecommunications companies, and consultants in the sector. The book will also prove very useful for scholars and practitioners in other parts of the world interested in comparing the EU system with their own.