本論文建立了一探討廠商從事水平與垂直差異化之Cournot數量競爭模型，討論廠商在競爭的市場結構下，如何決定創新投入的程度，以產品的差異化創造出更多的利潤。在處現今微利時代的競爭環境中，廠商研發創新的程度對其獲利能力的影響甚具研究價值。 本論文的主要結論如下。首先，創新的投入，不論是水平或是垂直差異化策略，確實是可影響廠商的競爭力及提高獲利能力；其次，在同一市場中的市場結構，即競爭廠商數目，也會影響創新所帶來的效益。 詳而言之，無論廠商從事水平或垂直差異化，第一、在雙占的市場結構下，均可能會有一個最適的產品差異化的程度，使得進行差異化的廠商能有較高的利潤；第二、在有多家競爭廠商的市場結構下，競爭廠商的多寡對廠商投入差異化努力的影響方向並不確定。當競爭廠商數不多時，競爭廠商數增加會使廠商投入差異化創新努力的誘因提高，但是當競爭廠商數很多時，更多的競爭廠商反而會降低廠商差異化創新努力的誘因。 ;By means of the Cournot model setting, we analyze how a firm invests on product differentiation innovation. The research is important, because we are now in a low-profit economic environment due to strict competition. The main findings of this research are as follows. Firstly, regardless of horizontal or vertical differentiation case, an investment an differentiation innovation could certainly raise the firm’s profit. Secondly, the market structure, i.e., the number of firms would affect the firm’s incentive of investment on differentiation innovation. In sum, there may exist an optimal investment on differentiation innovation for the firm in either horizontal or vertical differentiation case . In addition, the effects of the market structure on the investment are ambiguous. When the number of firms is small, more firms (or more competitive) will increase the firm’s incentive of investment. On the contrary, as the number of firms is large, i.e., a relatively competitive environment, more firms will reduce the firm’s investment on differentiation innovation.
