本文探討在異質產品且存在成本節省之R&D 下,分四種情況來探討政府的補貼政策:(i) 不存在補貼政策、(ii) 政府從事R&D 投資量補貼、 (iii)政府從事數量補貼與 (iv)政府同時對R&D 投資量與生產量做補貼。研究發現政府干預是有提升整體福利與減少過度生產與生產不足的問題,此外,在政府採用單一補貼政策的況下,數量補貼的福利效果大於R&D 補貼效果;然而,政府的最適政策(First-best policy)是同時對生產量做補貼並對R&D 投資量課稅。In the presence of cost-reducing R&D activity with heterogeneous product, wedivide the government’s subsidization into four regimes which are (i) Unsubsidizedpolicy, (ii) R&D subsidized policy (iii) Output subsidized policy and (iv) Both R&Dand Output subsidized policies. We demonstrate that government intervention isbeneficial to boost the social welfare and reduce the problems of underproduction andoverproduction; moreover, the output subsidy is better than the R&D subsidy in theindustry if the government only use single subsidized policy. However, governmentsubsidizes firms’ output and tax on R&D is the first-best policy.