We analyze the optimal dynamic policy of an antitrust authority towards horizontal mergers when merger proposals are … endogenous and occur over time. Approving a currently proposed merger will affect the profitability and welfare effects of … surplus by using a completely myopic merger review policy that approves a merger today if and only if it does not lower …

neglected. We introduce them into a standard oligopoly model of horizontal merger by assuming an (empirically supported …) decrease in labour demand due to merger-specific synergies and derive welfare effects. We find that efficiency benefits from …-side effects remain negligible. Eventually, policy conclusions for merger control are discussed. -- horizontal mergers …