This paper establishes a duopoly model with product differentiation and outsourcing in order to analyze the equilibrium competition strategies (choice of prices versus quantities) when the outsourcer outsources its intermediate good to a final product competitor. We show that: (1) both firms choose the quantity strategy when the cost efficiency of the subcontractor is low; (2) the choice of competition strategy is the price strategy for the subcontractor and the quantity strategy for the outsourcer when the cost efficiency of the subcontractor is moderate; (3) both firms choose the price strategy when the cost efficiency of the subcontractor is sufficiently high.
