本文乃將R&D內生成長模型中’考量中間財為獨占性競爭且具有 污染性之產業，據此探討若政府對中間財部門課徵污染稅，並專款專用 來從事防治污染支出，而對R&D部門之研發活動予以補貼，分別分析 此兩種政策對於經濟成長與社會福利會產生何種影響？透過比較靜態與 數值模擬分析的結果顯示，政府對中間財部門的污染課稅，除了可以改 善環境品質外，經濟體系亦分別存在一個「成長率極大之最適污染稅率」 與「福利極大之最適污染稅率」，使得經濟成長率與社會福利分別達到極 大。而對R&D部門補貼則有助於經濟成長，同時亦存在一個最適的R&D 部門補貼率，使得社會福利達到極大。

This paper integrates the R&D-based model with environmental protection, and sets the intermediate goods sectors as monopolistically competitive and as polluting industries. The government sector has two policies. One policy is to tax polluters, the intermediate goods sectors, for their pollution inputs to finance pollution prevention. The other policy is to impose a lump-sum tax on households to partially finance the subsidy expenditure for the R&D sector. This paper discusses how the two policies affect the economic growth rate and welfare. By comparative-static and numerical simulation analysis, we find that taxing polluters to finance pollution prevention will improve environmental quality. Moreover, there exists an “optimum pollution tax rate for economic growth” and an “optimum pollution tax rate for welfare” to maximize the economic growth rate and welfare, respectively. On the other hand, raising the R&D subsidy rate is helpful for increasing the economic growth rate. Furthermore, there exists an optimum R&D subsidy rate to maximize welfare.