HOW DID QUANTITATIVE EASING REALLY WORK? A New Methodology for Measuring the Fed's Impact on Financial Markets

This paper introduces a new methodology for measuring the impact of unconventional policies. Specifically, the paper examines how such policies reshaped market perceptions of how the Fed would behave in the future - not merely the expected path for policy rates, but how the central bank would adjust that path in response to different combinations of future inflation and growth. In short, it studies how quantitative easing affected investor beliefs about the future policy reaction function. The paper (1) proposes a novel model of market expectations for the central bank's future policy reaction function based on the Taylor Rule; (2) shows that empirical estimates of the model exhibit structural breaks that coincide with innovations in unconventional policies; and (3) finds that such policy innovations were associated with regime shifts in the behavior of 10-year U.S. Treasury yields, as well as unusual performance in risk assets such as credit spreads and equities. These findings provide evidence that a key causal channel for unconventional policies was via their impact on market expectations for the Fed's future policy reaction function. These shifts in expectations, in turn, appear to have had larger, more persistent, and more pervasive effects across financial markets than found in previous studies.