中国经济周期波动的福利成本研究——基于小概率“严重衰退”事件的视角

On the Welfare Cost of Business Cycle in China:An Alternative Perspective

本文在Lucas模型基础上,引入存在"严重衰退"状态的消费增长过程,重新估算中国经济周期的福利成本,修正了"Lucas论断"。通过本文模型的计算,我们得出:(1)应用存在"严重衰退"状态的福利成本模型估算的中国经济波动的福利成本远远高于Lucas模型估算的结果。在合理的参数范围内,前者一般是后者的10倍左右。因此,对于中国经济而言,旨在防止"严重衰退"状态发生的宏观稳定政策的福利收益相当大。(2)对于中国经济而言,降低"严重衰退"状态发生的概率(从0.017降低到0.003)所获得的福利收益大约是Lucas模型结果的3～4倍。这表明,中国宏观稳定政策的收益主要来源于降低"严重衰退"状态的发生概率,而不是减少通常意义上的经济波动。(3)在相对风险规避系数取值范围内(γ小于6),中国经济波动的福利成本与美国经济波动的福利成本相当接近。这从某种程度上说明了存在"严重衰退"状态的福利成本模型适用于不同的经济体。

This paper reconsiders the welfare costs of China＇s business cycles in an economy with a low probability, ＂serious recession＂ state in consumption growth. By applying of the new model to China＇s economy, we have come to： （1） The welfare costs of economic fluctuations are much higher than the results estimated by Lucas＇s model. Under reasonable parameters, the former may generally be about 10 times the latter. Hence, as far as the Chinese economy is concerned, the welfare gains of macrotabilization policies aimed at preventing the emergence of ＂serious recession＂ state will considerably be large. This conclusion provides a theoretical basis for the implementation of current stabilization policies in China. （2） As to the Chinese economy, the welfare gains obtained by reducing the probability of ＂serious recession＂ state from 0. 017 to 0. 003 are around 3 or 4 times the results calculated by Lucas＇s model. It shows that the gain of stabilization policies in China comes mainly from decreasing the probability of ＂serious recession＂ state rather than from smoothing economic fluctuations in the normal sense. （3） Within the range of relative risk aversion coefficient （ less than 6）, the welfare costs of economic fluctuations in China are very close to those in the U. S. It shows to some extent that the new model is applicable to different economies.