The economics of horizontal mergers: Unilateral and coordinated effects

This document builds on two reports commissioned by the European Commission on the economic analysis of horizontal mergers, dealing respectively with unilateral effects and tacit collusion. The document comprises four parts: Part A provides a general introduction and overview of the main issues. Part B focuses on the economics of unilateral effects, while Part C studies coordinated effects through the economics of tacit collusion. Part D reviews a number of quantitative procedures that can be used for the analysis of unilateral effects and tacit collusion.