Indeterminacy of Equilibrium and the Roles of Fiscal and Monetary Policies

本研究的重点是财政和货币政策在多重均衡经济体中的作用。我们首先研究了在存在均衡不确定性的情况下政策变化的影响。特别是，我们考察了当存在多个收敛均衡时是否会出现反直觉的政策效应，结果表明，结果严重依赖于生产技术和偏好结构的规格。我们已经在另类货币增长模型以及扭曲所得税的模型中揭示了这一事实。在处理货币增长模型时，我们同时考虑了货币持续增长规则和利率控制规则。在带有财政政策的模型中，我们考察了资本所得税、工资所得税和消费税的各种影响。我们研究的第二个目的是在比文献中使用的标准分析框架更一般的模型中考虑政策影响与均衡不确定性之间的关系。在此过程中，我们研究了(1)具有环境(负)外部性的增长模型，(2)具有内生职业选择的重叠世代模型，(3)具有知识扩散的内生技术变革模型，(4)具有R&D投资和税收的增长模型。通过考察这些特定的模型，我们发现了在存在均衡不确定性的情况下的各种政策含义。

This research focuses on the role of fiscal and monetary policies in the economies with multiple equilibria. We have first investigated the effects of policy changes in the presence of equilibrium indeterminacy. In particular, we examine whether or not counter intuitive policy effects emerge when there are multiple converging equilibria It is shown that the results depend heavily upon the specifications of production technology and preference structure. We have revealed this fact in alternative monetary growth models as well as in models with distortionary income taxation. In dealing with monetary growth models, we consider both the constant money growth rule and the interest rate control rule. In the models with fiscal policies, we have examined various effects of capital-income tax, wage-income tax as well as consumption tax.The second purpose of our research is to consider the relationship between policy impacts and indeterminacy of equilibrium in the models that are more general than the standard analytical frameworks used in the literature. In so doing, we have studied (1) a growth model with environmental (negative) externalities, (2) an overlapping generation model with endogenous occupational choice, (3) a model of endogenous technical change with knowledge diffusion, and (4) a growth model with R&D investment and taxation. By examining these specific models, we have found various policy implications in the presence of equilibrium indeterminacy.