'This paper provides a conceptual framework of multilateral bargaining in a bilaterally oligopolistic industry to analyze the motivations for horizontal mergers, technology choice, and their welfare implications. We first analyze the implication of market structure for the distribution of industry profits. We find that retailer mergers are more likely (less likely) if suppliers have increasing (decreasing) unit costs, while supplier mergers are more likely (less likely) if goods are substitutes (complements). In a second step we explore how market structure affects suppliers' technology choice, which reflects a trade-off between inframarginal and marginal production costs. We find that suppliers focus more on marginal cost reduction if (1) ...