How Effective is European Merger Control?

This paper applies a novel and intuitive approach based on stock market data to a unique dataset of large concentrations during the period 1990-2002 to assess the effectiveness of European merger control. We analyze the economic effects of the European Commission's merger control decisions and distinguish between prohibitions, clearances with commitments (either behavioral or structural), and outright clearances. We run an event study on merging and rival firms' stock prices to quantify the profitability effects of mergers and merger control decisions. The basic idea is to relate announcement and decision abnormal returns: merger control is effective if anticompetitive rents observed around the merger announcement are reversed by the antitrust decision, i.e. if there is a negative relation between announcement and decision abnormal returns. Our findings suggest that only outright prohibitions completely solve the competitive problems generated by the merger. Remedies are on average not effective in solving anticompetitive concerns, yet, we can qualify this finding. Remedies are more effective when they are applied during the first rather than the second investigation phase. Moreover, the European Commission appears to learn over time, since remedies are on average more effective in industries where they have been intensively applied before