Abstract

Monetary policy has long relied on the ‘natural rate hypothesis’, suggesting that after an economic shock the unemployment rate will automatically return to its supply-side ‘natural’ rate or NAIRU. Macroeconomic developments since the 2008 financial crisis have challenged this hypothesis, forcing the US Federal Reserve to conduct a strategic review of its monetary policy framework, published in 2020. We conducted an in-depth case study of the Fed through a content analysis of 120 speeches given by the Fed’s top-level body (FOMC) from 2012 to 2022. We show that policy learning has occurred in that FOMC members have problematised the NAIRU either on (1) epistemological grounds, acknowledging the risk of relying on NAIRU estimates, or on (2) ontological grounds, highlighting the endogeneity of the NAIRU to monetary policy. While both interpretations lead to a more expansionary monetary policy stance, the differing motivations matter for future policymaking. In the case of (1) the rationale is mainly to a avoid downward de-anchoring of inflation expectations, whereas with (2) it is to deliberately chase hot labour markets and a high-pressure-economy. Our speech analysis shows that (1) has been far more dominant in the FOMC, indicating incremental rather than fundamental ideational change.

摘要

货币政策长期以来依赖于“自然利率假说”，这表明在经济冲击之后，失业率将自动恢复到供给方的“自然”利率或 NAIRU。2008年金融危机以来的宏观经济发展对这一假设提出了挑战，迫使美联储对其2020年发布的货币政策框架进行战略审查。我们通过对120场演讲的内容分析，对美联储进行了深入的案例研究由美联储最高层机构 (FOMC) 从 2012 年到 2022 年给出。我们表明，政策学习已经发生，因为 FOMC 成员基于 (1) 认识论理由对 NAIRU 提出问题，承认依赖 NAIRU 估计的风险，或者基于(2)本体论依据，凸显NAIRU对货币政策的内生性。虽然这两种解释都会导致更加扩张的货币政策立场，但不同的动机对未来的政策制定很重要。在（1）的情况下，其基本原理主要是为了避免通胀预期的下行脱锚，而在（2）的情况下，其基本原理是有意追逐炎热的劳动力市场和高压经济。我们的演讲分析表明，(1) 在 FOMC 中占据主导地位，这表明观念的变化是渐进的，而不是根本性的。