本文的模型使用熊彼得 (Schumpeter) 的內生成長模型，考慮研發廠商面對創新困難程度的差異，分析在不同的產品品質研發階段和創新成功機率具有非線性關係之下，創新困難程度的提升會如何影響研發勞動投入量、社會的經濟成長率與整體社會福利水準。最後，本文探討政府對專利權的保護態度對整體社會福利造成的影響。本文研究發現，隨著研發商品品質不斷地提升，研發廠商面對的創新困難程度也同時提高，促使實質利率與經濟成長率位在較低的水準，並且拉低整體社會的福利。當政府補助比例、中間財產品品質提升幅度與勞動投入量的增加，三者都會提升實質利率與經濟成長率。而在專利廣度的討論下，當政府高度重視專利保護，廠商更加願意投入研發，使實質利率、經濟成長率與整體社會福利水準皆會獲得有效提升。

Based on Schumpeter's endogenous growth model, this thesis considers that R&D manufacturers face the different difficulty in R&D, and analyzes how will the difficulty in R&D affects labor input, social economic growth rate and social welfare under the non-linear relationship between different R&D stages and innovation success probability. Finally, this paper explores the impact of the government's attitude towards patent protection on social welfare. Three main findings emerge from the analysis. First, a higher degree of innovation difficulty will drive the real interest rate and economic growth rate to a lower level, and reduce the social welfare. Second, when increasing in the proportion of government subsidies, the improvement in the quality of intermediate goods and the labor input, these three situations tend to higher the real interest rate and economic growth rate. Third, under patent breadth, as an increase in the protection of the leading patent, manufacturers will have more willing to invest in R&D, and then the real interest rate, economic growth rate and social welfare level will be improved.

賴景昌 (2018)，內生經濟成長理論，逢甲經研所上課講義。
賴景昌 (2019)，內生經濟成長理論 : 品質提升模型，逢甲經研所上課講義。
賴景昌 (2021)，內生經濟成長理論 : R&D，政大經研所上課講義。
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