Buyer Power,Transport Cost and Welfare

Manufacturers produce substitute products and sell to consumers in a linear city through competing retail stores. A low cost store obtains large market share by selling at low prices. Assume that a big retailer may exert buyer power by demanding wholesale discounts from manufacturers. The model identifies exclusionary effects of buyer power against competing retailers. It is also found that certain level of buyer power of a discount retailer may maximize social welfare, while that of a regular price retailer may maximize total consumer surplus. Nevertheless, excessive buyer power hurts both consumers and society.