The strategic management literature has found it difficult to differentiate between collusive and efficiency-based synergies in horizontal merger activity. We propose a schematic to classify mergers that yields more information on merger types and merger effects, and that can, moreover,...

Using a sample of 186 referrals between 1965 and 2006, we analyse the abnormal returns experienced by UK bidding companies when a decision is made by UK regulators to refer a merger or acquisition for inquiry and when the decision is published by the regulator. We find evidence of disagreement...