This paper introduces the Werden-Froeb Index (WFI) to assist in evaluating merger-specific efficiencies in horizontal mergers. The index measures the weighted average reduction in marginal costs required to restore pre-merger equilibrium prices and quantities after the (full or partial) merger...

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...

Mergers that substantially lessen competition are challenged by antitrust authorities. Instead of blocking anticompetitive transitions straight away, authorities might choose to negotiate with the merging parties and allow the transactions to proceed with modifications that restore or preserve...

This paper applies a novel methodology to a unique dataset of large concentrations during the period 1990-2002 to assess merger control's effectiveness. By using data gathered from several sources and employing different evaluation techniques, we analyze the economic effects of the European...

Based on a database of 326 merger cases scrutinized by the European Commission between 1990 and 2007, we evaluate the economic impact of the change in European merger legislation in 2004. We ?rst propose a general framework to assess merger policy effectiveness, which is based on standard...

Using a sample of 167 mergers during the period 1990-2002 involving 544 firms either as merging firms or competitors, we contrast a measure of the merger's profitability based on event studies with one based on accounting data. We find positive and significant correlations between them when...

This report studies the importance of efficiency gains from horizontal mergers. A general theme throughout this report is that efficiency gains, and their pass-on to consumers, may vary substantially from merger to merger. For this reason it seems appropriate to reconsider current practice in...

We analyze the effects of synergies from horizontal mergers in a Cournot oligopoly where principals provide their agents with incentives to cut marginal costs prior to choosing output. We stress that synergies come at a cost which possibly leads to a countervailing incentive effect: The merged...

Die Aufwendungen für Online-Werbung sind in den vergangenen Jahren rasant gewachsen. Ihr Anteil am gesamten deutschen Werbemarkt lag 2007 bei sieben Prozent und die Tendenz zeigt weiter steil nach oben. Der Versuch von Microsoft, den weltweit zweitgrößten Suchmaschinenbetreiber, Yahoo, zu...

We examine the competitive effects of a passive partial ownership (PPO) when it serves as an instrument for the acquirer firm to learn the merger synergies with the target firm in advance. The realization of a synergy is uncertain ex ante, so that a direct merger exhibits a downside risk not...