We propose a general framework to assess merger policy effectiveness based on standard oligopoly theory and stock market reactions. We focus on four different dimensions of effectiveness: 1) legal certainty, 2) decision errors, 3) reversion of anti-competitive rents, and 4) deterrence. We apply...

This paper applies an 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. The basic idea is to relate announcement and decision abnormal returns. Under a set of four...