It is a fact that economics matters when it comes to competition law. Yet, the context for this book is the increasingly complex relationship of economic theory and competition law which gives rise to lively political and academic debate about the direction competition law should take in a more global and innovation-oriented market place. Adopting a comparative background, taking into account different situations in the US, Europe, Japan, transition and developing countries, the contributors to the book investigate the impact of economics on the objectives of competition law both in various fields of competition law enforcement – restrictive agreements, unilateral restraints, merger control – and on the effectiveness of enforcement in a given legal and judicial system.