政府投资、棘轮效应与宏观经济波动

Government Investment,Ratchet Effect and Macroeconomic Fluctuations

本文通过构建一个带有偶然性约束的DSGE模型,研究了逆周期政府投资调节对宏观经济波动的影响。研究发现:第一,政府投资的逆周期调节对于稳定产出具有积极作用;第二,由于向下刚性特征的存在,政府投资的扩张产生了棘轮效应,这可能导致政府债务攀升和对民间投资的抑制,进而影响宏观调控的效果;第三,政府越重视产出水平,公共品投资对于产出的促进作用就越强,当经济遭遇负向冲击后,棘轮效应越显著;第四,相比于允许民间资本进入公共品投资,减税政策和跨周期投资调节政策不仅缓解了政府投资的棘轮效应,对于稳定经济波动也具有更好的政策效果。据此,本文从优化政府投资结构、加强减税等政策的协调配合、完善跨周期政策设计三个方面提出了政策建议。

Against the background that China's economy is currently facing the triple pressure of demand contraction,supply shock and weakening expectations,government investment plays the more important role in stabilizing growth and smoothing economic fluctuations.The data shows that China's government investment not only has a typical countercyclicality,but also shows the trend of rapid and sharp rise followed by the slow decline,showing the obvious ratchet effect.On the basis of reviewing the literature,this paper uses a DSGE model with occasionally binding constraints to examine the ratchet effect of government investment and address the aforementioned questions.This paper finds that counter-cyclical government investment can effectively cope with the economic recession.However,due to the downward rigid constraints,the government investment cannot decline rapidly during the economic recovery period,which leads to the continuous high level of government investment and government debt.And the more the government values the level of output,the more the supply of public goods can boost output,the stronger the ratchet effect could be seen.The extension of the model further finds that:firstly,the public-private partnership model(PPP)stabilizes output to a certain extent,alleviates ratchet effect and reduces government debt ratio.Secondly,the tax reduction policy can not only reduce the scale of government investment by limiting government revenue,but also increase the level of output by stimulating private sector investment.Thirdly,when incorporating a cross-cycle adjustment design for government investment,the government proactively responds to the negative shocks in advance,resulting in smoother investment expenditure.In addition to strengthening the role of government investment in stabilizing the economy,it can also weaken the ratchet effect and reduce the government debt level.Accordingly,this paper puts forward the following policy suggestions.Firstly,optimize the structure and quality of government investment to prevent the potential ratchet effect of government investment right from the beginning.Secondly,strengthen the coordination and cooperation of policies such as tax cuts,strengthen the guiding and driving role of government investment,and stimulate the vitality of private investment.Thirdly,improve the cross-cycle policy design,strengthen medium-and longterm adjustments while smoothing out short-term fluctuations in the counter-cyclical period,and improve the expected management level of government investment.