Buyer power and exclusion in vertically related markets

Suppliers and consumer organizations have become increasingly concerned by the build-up of buyer power of retailers in many markets. A major concern is that strong retailers will abuse their power to exclude products and rival retailers from the market to be able to increase prices to consumers. As a consequence, remedies to limit buyer power are discussed and implemented in many countries. In this paper we compare the incentives for exclusion, and the effect on consumers prices, under both buyer and seller power. We study a model with a dominant upstream manufacturer and a competitive fringe of producers offering their products to two differentiated downstream retailers. We compare the equilibrium outcome of this model when i) the dominant supplier holds all the bargaining power, and (ii) the retailers have all the bargaining power. We show that full or partial exclusion of either the competitive product or downstream retailers occurs when inter and intrabrand competition are strong. This is true both under seller and buyer power. However, in contrast to the received literature, we find that buyer power weakly enhances welfare compared to seller power because buyer power will lead to both more product variety (less exclusion) and lower retail prices.