To overcome the limits on traditional monetary policy imposed by the effective lower bound on short-term interest rates, in recent years the Federal Reserve and other advanced-economy central banks have deployed new policy tools. This lecture reviews what we know about the new monetary tools, focusing on quantitative easing (QE) and forward guidance, the principal new tools used by the Fed. I argue that the new tools have proven effective at easing financial conditions when policy rates are constrained by the lower bound, even when financial markets are functioning normally, and that they can be made even more effective in the future. Accordingly, the new tools should become part of the standard central bank toolkit. Simulations of the Fed's FRB/US model suggest that, if the nominal neutral interest rate is in the range of 2–3 percent, consistent with most estimates for the United States, then a combination of QE and forward guidance can provide the equivalent of roughly 3 percentage points of policy space, largely offsetting the effects of the lower bound. If the neutral rate is much lower, however, then overcoming the effects of the lower bound may require additional measures, such as a moderate increase in the inflation target or greater reliance on fiscal policy for economic stabilization.

中文翻译：

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货币政策的新工具

为了克服短期利率的有效下限对传统货币政策的限制，近年来，美联储和其他发达经济体中央银行已经部署了新的政策工具。本讲座回顾了我们对新的货币工具的了解，重点是量化宽松（QE）和前瞻性指导，即美联储使用的主要新工具。我认为，当政策利率受下限限制时，即使在金融市场正常运行的情况下，新工具也能有效缓解金融状况，并且将来可以使其更加有效。因此，新工具应成为标准中央银行工具包的一部分。美联储FRB / US模型的模拟表明，如果名义中立利率在2-3％的范围内，与美国的大多数估算结果一致，量化宽松政策和前瞻性指导相结合可以提供大约3个百分点的政策空间，这在很大程度上抵消了下限的影响。但是，如果中性利率低得多，则要克服下限的影响，可能需要采取其他措施，例如适度提高通货膨胀目标或更多地依赖财政政策来稳定经济。