新冠肺炎疫情的宏观经济效应研究——基于嵌入灾难风险的新凯恩斯DSGE模型的数值模拟分析

Research on the Macroeconomic Effects of COVID-19:Numerical Simulation Analysis Based on New Keynesian DSGE Model with Disaster Risk

新冠肺炎疫情能够通过影响劳动力市场造成短期经济下行,而标准的宏观经济模型缺乏对其经济效应及内在传导机制的深入探讨。本文将劳动供给冲击和影响全要素生产率和劳动生产率的灾难风险冲击嵌入动态随机一般均衡模型,考察了新冠肺炎疫情影响国民经济的机制与效力。研究发现:第一,与常规意义上的灾难风险冲击不同,需求侧的产出下滑是供给冲击驱动的。疫情的影响并不直接表现为资本的实质性减损,而是劳动投入的减少与企业生产率的下降。第二,疫情同样会对国民经济运行带来负面影响,造成经济短期的滞胀。直接的劳动供给冲击造成就业严重下滑,随着疫情的好转,劳动供给冲击转化为企业生产率的下降,就业状况有所好转。第三,降低灾难风险冲击发生的概率、减轻灾难事件发生后生产率下降的幅度,以及缩短经济处于灾难状态的时长,均能有效降低疫情对国民经济的不利影响。第四,与财政补贴和降息政策相比,减税政策是后疫情时期扩大内需最有效的政策工具。

COVID-19 can cause short-term economic downturns by affecting the labor market,but standard macroeconomic models lack in-depth understanding of its economic effects and internal transmission mechanisms.By embedding labor supply shock and the disaster risk shock which affect total factor productivity and labor productivity into a dynamic stochastic general equilibrium model,this paper analyzes the mechanism and effect of COVID-19 on the national economy.The findings are as follows.Firstly,different from the normal disaster risk shocks,demand-side recession is caused by supply-side shocks.The impact of COVID-19 doesn’t manifiest as substantial loss of capital,but as the reduction of labor input and the decline of enterprise productivity.Secondly,the epidemic also has a negative impact on the operation of the national economy,resulting in economic stagnation in short-term.The direct labor supply shock causes a serious decline in unemployment.With the improvement of epidemic prevention and control,the labor supply shock turns into a decline in enterprise productivity,and the employment situation improves.Thirdly,reducing the likehihod of disaster risk shocks,holding back the slowdown of post-disaster productivity,and shortening the length of time that disaster drags on economye can effectively reduce the adverse impact of the epidemic on the national economy.Fourthly,compared with fiscal subsidies and interest rate reduction,labor income tax reduction is the most effective policy tool to expand domestic demand in the post-epidemic period.