This two-volume collection presents the most important recent articles on empirical issues in industrial organization, related primarily to the analysis of imperfect competition.These two volumes offer a carefully selected set of contributions to empirical industrial organization. Replete with classics, but resolutely forward-looking, they provide the reader with both methodological tools and insights into the working of many imperfectly competitive markets of our modern economies. A must-read for anyone interested in industrial organization. -- Jean Tirole, Institut d'Economie Industrielle, University of Toulouse, France