This article recalls the evolution of the economic analysis of horizontal mergers and examines its relevance for competition policy. Since the pionner article by Williamson which showed, within a “naive model”, the arbitrage between productivity gains and the price increase due to greater market power, recent contributions, taking into account the strategic reaction of competitors and the asymmetric information context in which competition authorities operate, militate in favor of thougher regulations, lessening the rather liberal message of Williamson.
CHARLETY-LEPERS, P. et SOUAM, S. (2002). Analyse économique des fusions horizontales. Revue française d’économie, pp. 37-67.