数字金融、严重负向冲击与非常规货币政策

Digital Finance,Severe Negative Shock and Unconventional Monetary Policy

21世纪以来,较为频繁地遭受外部负向重大冲击的时代背景催生了对中国非常规货币政策理论体系构建与实践指引的双重需求。基于非常规货币政策效果取决于金融市场摩擦程度的理论逻辑,从近年来给中国金融结构和金融运行机制带来颠覆性影响的数字金融出发,本文尝试从理论上回应上述问题。研究发现,常规与非常规货币政策的区别可归结为中央银行资产总量和结构调整的差异,前者调控货币市场利率水平,后者调控不同金融资产市场间的利差。在经济遭受严重负向冲击时期,基准利率调控受到有效利率下限的限制,而冲击会放大利差水平,因而非常规货币政策更为有效。数字金融影响非常规货币政策的相对效果,是基于利率和利差变动对企业投资影响的相对大小实现的,数字金融发展水平越高,影响效果越大。本文将中国特色经济发展与传统理论逻辑纳入统一的框架,并提出中国常规与非常规货币政策选择不仅是经济波动的函数,还是金融发展水平的函数。本文对于新时期如何根据经济冲击特征创新和健全货币政策调控方式,以实现党的二十大报告提出的经济高质量发展具有重要的政策启示。

China has frequently suffered from negative external shocks after entering the 21st century,which has given rise to the use of unconventional monetary policy and the demand for building a theoretical system to guide the practice in a large transitional economy with unique characteristics like China.We attempt to explain the theoretical logic that the effect of unconventional monetary policy depends on the degree of financial market friction,and explore how digital finance affects the effectiveness of China's unconventional monetary policy transmission against the background that digital finance has caused disruptive impacts on China's financial structure and financial operation mechanism in recent years.We investigate the empirical evidence using the OLS method and explain them by constructing a theoretical model with dual financial frictions and heterogeneous firms and banks.The findings of this paper are as follows.First,the conventional monetary policies affect central bank's asset size,while the unconventional monetary policies affect central bank's asset composition.The former influences the interest rate in the money market,while the latter affects the spread between different financial asset markets.Under severe negative shocks,the money market interest rate may approach the effective lower limit of interest rate and cannot be reduced further,so the conventional monetary policy cannot stimulate the economy and achieve recovery.Meanwhile,the negative shock widens the interest rate spread caused by financial frictions,while the unconventional monetary policy can mitigate financial frictions and narrow the interest rate spread,so it is more effective than conventional monetary practices.Second,digital finance has marginal effects on both conventional monetary policy and unconventional monetary policy.The impacts of digital finance on the relative of effectiveness of unconventional monetary policy to conventional monetary policy depend on how it relatively influences interest rate spread and the money market rate and how they stimulate firm investment.Third,the marginal impact of digital finance on the investment stimulating effect of unconventional monetary policy is heterogeneous across firms,which depends on how digital finance improves financial frictions in the credit market and the completeness of interest rate corridor.This paper unifies unique characteristics of Chinese financial market and the theoretical logic.The choice between conventional and unconventional monetary policies in China depends on not only the features of business cycle fluctuation but also characteristics of financial development.It provides important policy implications for how to achieve the combination of efficient market and active governance in the new era,as well as improve the market-oriented equilibrium interest rate formation and transmission.