Horizontal Mergers and Innovation in Concentrated Industries

The relationship between mergers and the long run rate of innovation is an open question in antitrust economics. I develop a framework to examine this in a dynamic oligopoly model with endogenous investment, entry, exit and horizontal mergers. Firms produce vertically differentiated goods and may merge with rival firms to gain market power and potentially increase the quality of their product. I extend previous work on dynamic mergers by allowing for products differentiated on quality with competition in prices and an endogenous long run rate of innovation. In equilibrium, horizontal mergers are almost entirely harmful to consumers in the short run, but the prospect of a buyout creates a powerful incentive for firms to preemptively enter the industry and invest to make themselves an attractive merger partner. The result is significantly higher rate of innovation with mergers than without and significantly higher long-run consumer welfare as well. Further results explore the circumstances under which this result is likely to hold. In order for the long run increase in innovation to outweigh the short run harm to consumers caused by mergers, entry costs must be low, entrants and incumbents must both have the ability to innovate rapidly, and the degree of horizontal product differentiation must be low. Alternatively, when mergers can generate innovation directly by allowing firms to combine their products they typically benefit consumers in both the short run and long run.