台灣現今的科技產業面臨嚴峻競爭，尤其在全球化下市場下，廠商需要在生產製程或商品的創新上投入R&D，以求提升競爭優勢。因此，從商品循環週期之中，我們可以看見廠商由獨占的地位變成寡占於市場。為了要清楚分析廠商的市場與R&D行為，本論文以D’Aspremont and Jacqumin (1988)一文的Cournot產量競爭與製程R&D理論模型為基礎，進一步分析當市場為Bertrand價格競爭與Stackelberg產量競爭時，探討存在R&D外溢效果下，雙占廠商進行R&D的策略行為。本論文得出以下四個主要結論：(一)在Bertrand價格競爭的情況下，當市場處於成長時期，則商品市場越競爭，會使廠商的R&D投入越多；(二)在Bertrand價格競爭的情況下，當市場處於成長時期，則當商品的同質性越高，兩廠商越不會進行R&D合作；(三)在Stackelberg產量競爭的情況下，當市場處於成長時期，領導廠商的R&D投入較追隨廠商多；(四)在Stackelberg產量競爭的情況下，當市場處於成長時期，無論外溢效果為何，領導廠商皆不會採取合作的方式進行R&D。;The competition faced by technology industry in Taiwan is tough now. Taking firms in semiconductor industry for example, they execute R&D in the production process or product innovation to enhance the competitive advantage. Therefore, from the viewpoint of the commodity cycle, we can see the firm who has been a monopolist will face an oligopolistic market when there appears other competitor. In order to analyze vendor market behavior clearly, we refer to D’Aspremont and Jacqumin (1988) but consider the market to be Bertrand price competition or Stackelberg quantity competition to build new models to investigate the impact of the R&D spillover effect on firms’ R&D strategies. We have the following four findings. First, under Bertrand competition, when market is more competitive, the more R&D investments the firms will invest. Second, under Bertrand competition, when the product is more similar, the possibility of cooperation in R&D by the two firms is smaller. Third, under Stackelberg competition, the leading firm will invest more R&D than the follower. Fourth, under Stackelberg competition, whatever the scale of the spillover effect, the leader will not cooperate to execute R&D.
