We study welfare effects of horizontal mergers under a successive oligopoly model and find that downstream mergers can increase welfare if they reduce input prices. The lower input price shifts some input production from cost- inefficient upstream firms to cost-efficient ones. Also, the lower...

In this paper we argue that two important causes of welfare losses in oligopolistic markets have been neglected. We show that in models where location is endogenous, welfare losses arising from wrong locations or from lack of market coverage may be substantial despite firms competing in prices....