贝莱德研究主管：美联储货币政策转变会有哪些潜在影响？

美联储正在考虑改变其货币政策框架。贝莱德投资研究所经济与市场研究主管Elga Bartsch撰文，评估了这种改变对市场和经济的潜在影响。

图片|视觉中国

美联储正在考虑将其货币政策框架从灵活的通胀预测目标转变为几种补偿策略中的一个。

The Federal Reserve is considering a changing its monetary policy framework from flexible inflation forecast targeting to one of several strategies known as make-up strategies.

这对市场和经济可能意味着什么？在这篇文章中我深入探讨了潜在影响，本文是美联储潜在转变的一系列博客文章中的最后一篇。

What does this potentially mean for markets and the economy? I delve into the potential impact in this post, the final in a series of blog posts on the Fed’s potential shift.

在比较美联储当前货币政策体系的有效性与正在考虑的补充策略替代方案（包括平均通胀目标（AIT）和价格水平目标（PLT））的潜力时，出现了几个共同的主题。美联储和中央银行界以外的学者对此进行了广泛的研究。数千个模型结果可以概括为四个补偿策略的主要特征。

A few common themes emerge when comparing the efficacy of the Fed’s current monetary policy system with the potential of the make-up strategy alternatives under consideration, including average inflation targeting (AIT) and price level targeting (PLT). Extensive studies on this topic have been done by the Fed and academics outside of the central banking world. Thousands of model outcomes can be summarized into four main features of make-up strategies.

1. 经济在衰退后更迅速地恢复到平稳状态（在稳定状态下，通胀率达到目标，并且产出缺口缩小）。

2. 利率可能会长期保持在较低水平。如果美联储在全球金融危机后采取了一系列补偿策略中的任何一种，它可能不会从危机后的低点开始加息，即使至今为止。

3. 宏观经济波动可能会减少。

4. 资产泡沫可能会变得更加普遍——除非在补偿策略运作时收紧宏观审慎规则。

1. The economy returns more quickly to a steady state (where inflation is at target and the output gap is closed) after a downturn.

2. Interest rates would likely stay lower for longer. If the Fed had adopted any one of a number of make-up strategies after the global financial crisis, it would probably not have started to raise rates from post-crisis lows – even by now.

3. Macroeconomic volatility could decrease.

4. Asset bubbles could become more common – unless macro prudential rules are tightened when make-up strategies are in place.

有关金融市场如何应对三种潜在情况的更详细信息，请参阅下表。

See the table below for a more detailed look at how financial markets could respond to three potential scenarios.

如果实施一项新的策略，当前美国的货币扩张可能需要数年的时间。这是因为考虑补偿策略的意愿表明，长期利率较低，因此偏向于更宽松而不是更紧缩的货币政策，而且政策失误导致扩张周期缩短的可能性较低。但是，由于金融脆弱性很可能会更快地积聚起来，因此需要密切监控经济复苏的其他潜在风险。

The current U.S. expansion could have years more to run if a new strategy were implemented. This is because the willingness to consider make-up strategies suggests lower-for longer interest rates and therefore a bias toward easier rather than tighter monetary policy – and a lower chance that a policy mistake could cut short the expansion. But other potential risks to the recovery would need be monitored closely because financial vulnerabilities would likely build up faster.

如果美联储决定实施补偿策略，我们相信，未来出现极端宏观结果的可能性或会降低，特别是由于缺乏货币政策火力，经济衰退进一步恶化为全面萧条的情况。这是因为利率下限可能不会经常成为限制因素。我们认为，全面通货紧缩的风险也会下降。这些负面事件发生的可能性越低，加之长期利率的降低和长期通胀预期的提高，可能支持风险资产。

If the Fed decides that a make-up strategy should be implemented, we believe that the future chance of extreme macro outcomes – especially a recession deepening into a full-blown depression because of a lack of monetary policy firepower – may be reduced. This is because the interest-rate floor may not become a limiting factor as often. The risk of full-blown deflation would also decline, in our view. The lower chance of these negative events – combined with lower-for-longer interest rates and higher long-term inflation expectations – would likely support risk assets.

以历史标准衡量，目前较低的波动性，也可能发生变化。在可依赖的补偿策略下，中期宏观经济波动可能会下降。在市场消化美联储任何新的通胀策略的同时，短期内波动率也可能上升。将需要有效的美联储沟通来管理这一转变。

Volatility – currently low by historical standards – could also change. Medium-term macroeconomic volatility would likely decline under credible make-up strategies. Volatility could also rise in the short term while the market digests any new Fed inflation strategy. Effective Fed communication would be needed to manage this transition.

但在现实中，任何实际的AIT的实施（或其他补偿策略）都可能被稀释。正如美联储的Richard Clariada今年5月所说，“我们的审查更有可能在我们实施货币政策的方式上产生进化，而不是革命。”越多的央行官员说不会有大变化，其可能产生的影响就越小。

But in reality, any actual implementation of AIT (or other make-up strategies) is likely to be diluted. As the Fed’s Richard Clarida said in May this year, “our review is more likely to produce evolution, not a revolution, in the way we conduct monetary policy.” The more central bankers say there won’t be a big change, the lesser the likely impact.

政策制定者可能只会在下一次经济衰退期间引入新的战略。他们也可能对金融过热以及由此带来的金融稳定风险持谨慎态度。重要的是，AIT依赖于对通胀预期的成功操纵，而在经济复苏期间，央行官员们一直未能有效地做到这一点。正在被提出的一些弥补策略，例如“临时”或“目标”PLT，可能会遇到与中央银行预先给出特定政策承诺相关的时间不一致问题。最后必须考虑的是：如果在没有具体说明将采取哪些措施来引起通胀超调的情况下实施AIT，政策效果将受到损害。

Policymakers may only introduce a new strategy during the next downturn. They may also be wary of financial overheating and the resulting risks to financial stability. Importantly, AIT depends on the successful manipulation of inflation expectations, something central bankers have been unable to effectively do during this economic recovery. Some of the make-up strategies being proposed – such as “temporary” or “targeted” PLT – could suffer from time inconsistency issues relating to the challenge of central banks to pre-commit to a specific policy promise. A final consideration: AIT would be undermined if it were implemented without specifying the steps that would be taken to bring about inflation overshoots.

我们的底线|Our bottom line

美联储货币政策手册变化的实际影响可能只是AIT和其他补偿策略在书面上承诺的影子——除非该策略的变化伴随着通胀目标本身的上调。

The actual impact of a change in the Fed’s monetary policy playbook may only be a shadow of what AIT and other make-up strategies promise on paper – unless the change in the strategy comes with an upward adjustment to the inflation target itself.

注：Elga Bartsch博士为贝莱德投资研究所经济与市场研究主管。

Elga Bartsch, PhD, Head of Economic and Markets Research for the BlackRock Investment Institute, is a regular contributor to The Blog.