Strategic Merger Approvals Under Incomplete Information

We examine a signaling game where the merging entity privately observes the cost-reduction effect from the merger, but the competition authority does not. The latter, however, observes the firm's submission costs in the merger request, using them to infer its type. We identify pooling equilibria where all firm types, even those with small efficiencies, submit a merger request, which is approved by the regulator. This merger profile cannot be supported under complete information, thus leading to inefficiencies. We investigate under which parameter conditions inefficient mergers are less likely to arise in equilibrium, and which policies hinder them, ultimately improving information transmission from firms to the competition authority.