Horizontal Mergers, Involuntary Unemployment, and Welfare

Standard welfare analysis of horizontal mergers usually refers to two effects: the anticompetitive market power effect reduces welfare by enabling firms to charge prices above marginal costs, whereas the procompetitive efficiency ef-fect increases welfare by reducing the costs of production (synergies). How-ever, demand-side effects of synergies are usually 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 horizontal mergers are substantially decreased, if involuntary unemployment exists. However, in full employment economies, demand-side effects remain negligible. Eventually, policy conclusions for merger control are discussed.