Consumption Externalities and Macrceconomic Dynamics

本研究的目的是探讨消费外部效应在世代重叠经济中的作用。现有的关于具有消费外部性的宏观动力学模型的研究大多采用具有代表性的代理模型。由于私人消费水平和平均消费水平在代表性的代理经济中相互吻合，因此在大多数研究中，消费外部性的影响大多是定量的而不是定性的。通过在代理人的消费活动中引入外部效应，我们扩展了标准的两阶段OLG资本积累模型。代表性代理人和OLG设置之间的关键区别在于，消费的同时外部效应涉及代际以及代际内的OLG经济外部性。本项目的总体结论是，OLG经济的动态行为很大程度上取决于如何指定的消费外部效应。我们发现，即使是简单的模型也可能产生多个稳态和平衡的不确定性。此外，在模型经济中的政策含义将是根本不同的代表性代理人对应的。我们已经证实了这些事实的背景下，替代设置的OLG经济体的各种规格的优惠和技术。

The purpose of this study is to explore the role of consumption external effects in overlapping generations economies. Most of the existing investigations on macrodynamic models with consumption externalities have utilized the representative agent models. Since the private and average levels of consumption coincide each other in the representative agent economies, the effects of consumption externalities are mostly quantitative rather than qualitative in most of the foregoing studies. We extend the standard two-period lived OLG models of capital accumulation by introducing external effects among consumption activities of the agents. The key difference between the representative agent and the OLG settings is that the contemporaneous external effects of consumption involve the intergenerational as well as intragenerational externalities in the OLG economy.The general conclusion of this project is that the dynamic behaviors of OLG economies heavily depend on how the consumption external effects are specified. We have found that even simple models may yield multiple steady states and indeterminacy of equilibrium. In addition, policy implications in the model economies would be fundamentally different form those obtained in the representative agent counterpart. We have confirmed these facts in the context of alternative settings of OLG economies with various specifications of preferences and technologies.