从量化宽松到量化紧缩——美联储缩减资产负债表的决定因素及其影响

From Quantitative Easing to Quantitative Tightening Determinants and Effects of Federal Reserve's Balance Sheet Shrinkage

作为货币政策正常化的第二阶段,美联储将在2017年开始缩减因危机后实行的量化宽松政策而形成的规模庞大的资产负债表,并指出缩表结束后的证券资产持有规模将不会大于为有效执行货币政策所必须维持的水平。本文认为,决定美联储资产负债表长期规模的主要因素是美联储负债中的流通中货币量和准备金余额的长期水平,前者取决于美联储对未来名义GDP增长趋势的估计,后者则取决于美联储对未来货币政策执行框架的选择。如果美联储倾向于采用危机前的公开市场操作办法,准备金余额的长期水平将与银行交易性存款余额决定的必要准备金水平趋于一致,美联储资产负债表的长期规模将因此显著低于目前的水平。相反,如果依照本文所预计的,美联储将继续危机后实行的利率走廊机制,以超额准备金利率和隔夜反向回购利率控制联邦基金利率的变动范围,准备金余额的长期水平就将由银行对准备金的需求来决定。在这种情况下,美联储资产负债表的规模虽会在目前的基础上缩减,但程度相对有限,因而对经济的负面影响较小。此外,和危机前的以提高联邦基金利率作为紧缩性货币政策的主要工具不同,本次量化紧缩政策的特点是美联储可以同时运用短期利率和资产负债表两种政策工具,意味着美联储能够通过资产负债表的缩减来部分地取代联邦基金利率的提高,而不至于改变紧缩性货币政策的总体效果,这在一定程度上将缓和升息对经济造成的负面影响。

As phase two of the policy normalization, Federal Reserve will shrink its outsized balance sheet this year and the Treasury holdings on the balance sheet, once normalization is achieved, will not be higher than the level which is nec- essary to implement its monetary policy. Since the longer-run size of the Federal Reserve＇s balance sheet is largely deter- mined by growth trend of the amount of currency in circulation as well as bank reserves balance, the size of the Federal Re- serve＇s balance sheet will ultimately he determined by growth in normal GDP and the operational framework it chooses for implementing its monetary policy. If the Federal Reserve prefers to go back to the pre-erisis operating system with minimal excess reserves and no reverse repo facility, its assets would have to shrink dramatically so that to drain reserves back to the required reserve level. By contrast, if the Federal Reserve chooses to preserve its new operating system as we predict, with interest rate on bank reserves and reverse repo rate served as ceiling and floor of the interest rate corridor, then the balance sheet would not need to shrink as much and level of the reserves will depend on growth in reserve needs. In the latter case, the effects of Federal reserve＇s balance sheet shrinkage on financial conditions and the economy will likely he modest. Fur- thermore, since the Federal Reserve can now use both the funds rate and the balance sheet as its policy tools, shrinking the balance sheet over the next few years may substitute for a couple of hikes in the funds rate so that it can not only achieve the same degree of overall policy tightening, but also mitigate negative impact of the funds rate hike on the economy.