技術領導國的專利長度──疊代模型的分析

THE PATENT LENGTH IN THE TECHNOLOGYLEADING COUNTRY: ANALYSIS WITH AN OVERLAPPING GENERATIONS MODEL

當本文的主要目的在於探討技術領導國的專利期限長度對技術領導國與追隨國的經濟成長及社會福利的影響。需求面依循Blanchard（1985）所設定的疊代模型，供給面則依照Barro and Sala-i-Martin（1997）所提出的技術領導國與技術追隨國架構。本文發現：坽在疊代模型下，技術領導國延長專利期限長度對兩國的經濟成長與社會福利的影響效果皆不確定;夌利用合理的參數進行數值分析的結果後發現，技術領導國延長專利期限長度將提高兩國的經濟成長率，對兩國社會福利的影響效果卻不確定。在疊代的架構下，過長的專利期限可能會減損技術領導國的福利，而技術追隨國的福利效果則受限於模仿成本的彈性。

This paper explores how the extension of patent length in the technology-leading country affects the growth and welfare of its citizens and of those in the technology-following country. The demand side of the economy is based on the overlapping generations model developed by Blanchard (1985), and the supply side of the economy is based on the technological diffusion model developed by Barro and Sala-i-Martin (1997). Two main conclusions emerge. First, theoretical analysis suggests that extension of patent length in the technology-leading country has ambiguous effects on the economic growth and social welfare of both countries in the overlapping generations model. Second, numerical simulation suggests that the extension of patent length in the technology-leading country raises the economic growth of both countries, but has ambiguous welfare effects on both countries. In the overlapping generations model, extending the patent term may reduce the social welfare of the technology-leading country, while the effects on the social welfare of the technology-following country depend on the elasticity of imitation costs.