Buyer Group and Buyer Power When Sellers Compete

Résumé

We study how the formation of a buyer group affects buyer power when sellers compete and buyers operate in separate markets. Previous research (Inderst and Shaffer, 2007, and Dana, 2012) has considered a buyer group that can commit to an exclusive purchase and has found that the formation of a buyer group strictly increases buyer power unless buyers have identical preferences. In contrast, we assume that no commitment to exclusive purchases is possible. We find that the formation of a buyer group has no effect if each seller's cost function is concave. If it is strictly convex, the buyer group strictly reduces the buyers'total payoff as long as the Pareto-dominant equilibrium for sellers is played when a buyer group is formed.