Downstream competition and profits under different input price bargaining structures

In a vertically related duopoly with input price bargaining, this paper re-examines the downstream firms’ profitability under different market competition degrees. Downstream firms earn highest profits with semi-collusion whose level depends on product differentiation and relative parties’ bargaining power. Holding fixed the upstream suppliers’ bargaining power, the more the products are differentiated, the higher the downstream firms’ collusive level that maximize profits, regardless of the negotiations’ structure. On the other hand, holding fixed the product differentiation degree: 1) with uncoordinated bargaining, the higher the upstream suppliers’ bargaining power is, the lower the downstream firms’ collusive level is; 2) with upstream firms’ bargaining coordination, a U-shaped relation exists between the upstream firms’ power and the downstream firms’ collusive level that maximizes their profits.