高宏Chapter2A概论.ppt

Chapter 2 Infinite-Horizon and Overlapping-Generations Model 周泳宏 tzhouyhjnu@jnu.edu.cn Introduction This chapter investigates two models Ramsey-Cass-Koopmans Model Diamond Model Both the models continue to treat the growth rates of labor and knowledge as exogenous But derive the evolution of the capital stock from the interaction of maximizing households and firms in competitive markets The saving rate is endogenous Modern theoretical macroeconomics research uses models based upon individual micro-optimising behaviour over time. There are two basic structural models upon which modern macroeconomic theory is based. The Ramsey-Cass-Koopmans model The Overlapping Generations or Diamond model The central difference between the Diamond model and the Ramsey-Cass-Koopmans model is that Ramsey: there is a fixed number of infinitely lived households Diamond:there is turnover in the population New individuals are continually being born, and old individuals are continually dying Part A Ramsey-Cass-Koopmans model Introduction The Ramsey model is a general equilibrium model in which households and firms interact in competitive markets. The production side (firm) of the economy is identical to that used in the Solow model. The household side consists of a ‘representative agent’ who owns the capital, supplies the labor used by firms, and consumes or saves the resulting output. Firms pay rent and wages to the households who decide how much to spend on consumption (revenue for the firms) and how much to save (invest in new capital). The heart of the model is the consumption/saving decision and this is based on micro-optimising behaviour. Given the parameters,the representative agent chooses the consumption/saving plan that maximises their (expected) discounted lifetime utility. 模型假设 完全竞争市场结构 长生不老的不断扩展的家庭 家庭和个人完全同质 忽略资本的折旧 2.1 Assumptions 1）Firms The economy is viewed as consisting of a large number of identical firms. With perfectly competitive markets, factor retu