Research on the Financial Accelerator Hypothesis and Financial Instability from the Perspectives of International Economy

本文从金融不稳定理论的角度考察了金融经济与宏观经济的关系。宏观经济模型是在凯恩斯模型和货币主义模型的基础上建立起来的。然后，我们考虑了稳定性条件，并比较了两种模型差异背后的原因。并结合国际上真实的现象对金融加速器理论进行了分析。以下是研究结果。要使短期市场均衡稳定，货币需求对利率的速度和弹性的倒数需要很小.货币数量理论在短期、中期和长期都是有效的。自然失业率在长期均衡模型中并不领先。要使市场长期均衡稳定，速度的倒数应超过我们模型所给出的下限。下限是储蓄率和货币需求对预期通货膨胀率的弹性的递减函数。对于金融加速器假说的关注，本文认为，信贷总量与宏观经济活动的关系取决于投资者在投资组合选择中的相对风险厌恶程度。如果相对风险厌恶程度足够高，宏观经济就会因信用波动过大而变得脆弱。这一点也得到了我们的计量经济学分析的证实。

We investigated the relationship between Financial economy and the Macro Economy from the View Point of Financial Instability Theory. Macro Economic Models were built on the basis of Keynesian Model and Monetarist Model. Then we consider the stability condition and compare the reason behind the differences in both Models. In addition, Financial Accelerator Theory was analyzed with taking into account of the real phenomenon in the world. Followings are results from research.1. To make short-time market equilibrium stable, a reciprocal number of velocity and elasticity of money demand against interest rate need to be small.2. Quantity theory of money is functional in the short, medium, long-term. Natural rate of unemployment is not lead in the long term equilibrium model3. To make long-term market equilibrium stable, a reciprocal number of velocity should be over the lower limit lead by our model. The lower limit is decreasing function of saving rate and elasticity of money demand against expected rate of inflation. But it is increasing function of elasticity of investment against interest rate.As for the concerning of financial accelerator hypothesis, we concluded that the relationship between aggregate credit and macro economic activities depend the degree of relative risk aversion of investors in their portfolio selection. If the degree of relative risk aversion is enough high, macro economy become fragile due to the large variation of credit. Those are also confirmed by our econometric analysis.