美联储超常规货币政策的历史回顾与作用机制分析

Historical Review of Federal Reserve’s Unconventional Monetary Policies

金融危机之后,主要发达经济体先后实施了超常规的货币政策。理论上,超常规的货币政策能压低长期实际利率,向银行体系注入基础货币,并改善信贷扩张的条件,因此能稳定增长、促进就业、加速通胀。但现实中的政策效果却在多个方面超出了理论预期。本文从四个方面对美联储的超常规货币政策进行了历史回顾。首先,先后三轮QE在稳定增长、带动就业、加速通胀上表现各异:QE1实现了V形反转,QE2引发了轻度滞胀,QE3规模更大持续期更长,但效果却并不明显。其次,作为政策中介变量,中长期实际利率能否被引入下行路径,是QE能否取得政策效果的关键。再次,超常规的货币政策并没有加速通胀,反而伴生了全球性的通胀率下降,这动摇了通胀目标制的合理性。最后,量化宽松退出与加息进程启动对全球经济存在明显的溢出效应。

Developed economies have implemented unconventional monetary policies during the postcrisis era.In theory,the unconventional monetary policies could lower the real long-term interest rates,and then promote growth and employment,and accelerate inflation.However,the actual policy effects have exceeded theoretical expectations in many aspects.First of all,the performance of the three rounds of QE were varied:QE1 achieved a V-shaped reversal,QE2 caused a stagflation,while QE3 was less effective even though it had larger scale and longer duration.Secondly,as the intermediate variable,the longterm real interest rate could effectively explain weather the QE could successfully achieve its targets.Thirdly,the unconventional monetary policies did not accelerate inflation,on the contrary,there is a disinflation in US and globally,which has weakened the rationality of the inflation targeting rule.Finally,the exit of quantitative easing and the start of the rate hike may have significant spillover effects on the global economy,which in turn could feedback on the US itself.