A Schumpeterian Model of the Product Life Cycle
构建了一个南北贸易的动态一般均衡模型，其中企业间的研发竞赛决定北方的产品创新速度。分析表明，保护北方夕阳产业的关税会减少北方主导企业数量、降低创新率并提高北方工人相对工资。
This paper presents a dynamic general equilibrium model of North-South trade in which research and development races between firms determine the rate of product innovation in the North. Tariffs designed to protect dying industries in the North from Southern competition reduce the steady-state number of dominant firms in the North, reduce the rate of product innovation, and increase the relative wage of Northern workers. Copyright 1990 by American Economic Association.