In 2012–2013 the European Commission has had particularly prominent merger cases, with two prohibitions of transactions and several clearances with far-reaching remedies. In these cases economic analysis has been tightly integrated into the general argument of the Commission and became central to the outcome of the cases. Based on economic theory and supporting data, the Commission has pursued novel economic theories of harm and challenged some economically dubious “common wisdom” in merger assessment. The second area in which economic analysis has had a major impact is in state aid modernization. The new regional aid guidelines of 2013 have moved the rules much closer to economic thinking about effective regional aid and introduced requirements for economic ex-post analysis. Finally, the decisions on the e-books case reflect close cross-Atlantic cooperation with respect to the economic analysis and the design of appropriate remedies. This article reports on a number of examples for the most important cases.