The first MaCCI-EPoS-CREST Workshop on Industrial Organization covered empirical and theoretical research on a number of industrial organization issues. Presenters from CREST were Marie-Laure Allain, Philippe Choné, Xavier d'Haultfoeuille, Laurent Linnemer and Julien Monardo, presenters from MaCCI were Esteban Cattaneo, Volker Nocke, Nicolas Schutz, Anton Sobolev, and Michelle Sovinsky.