Measuring the Effect of the Zero Lower Bound on Medium- and Longer-Term Interest Rates

The federal funds rate has been at the zero lower bound for over four years, since December 2008. According to many macroeconomic models, this should have greatly reduced the effectiveness of monetary policy and increased the efficacy of fiscal policy. However, standard macroeconomic theory also implies that private-sector decisions depend on the entire path of expected future short term interest rates, not just the current level of the overnight rate. Thus, interest rates with a year or more to maturity are arguably more relevant for the economy, and it is unclear to what extent those yields have been constrained. In this paper, we measure the effects of the zero lower bound on interest rates of any maturity by estimating the time-varying high-frequency sensitivity of those interest rates to macroeconomic announcements relative to a benchmark period in which the zero bound was not a concern. We find that yields on Treasury securities with a year or more to maturity were surprisingly responsive to news throughout 2008–10, suggesting that monetary and fiscal policy were likely to have been about as effective as usual during this period. Only beginning in late 2011 does the sensitivity of these yields to news fall closer to zero. We offer two explanations for our findings: First, until late 2011, market participants expected the funds rate to lift off from zero within about four quarters, minimizing the effects of the zero bound on medium and longer-term yields. Second, the Fed’s unconventional policy actions seem to have helped offset the effects of the zero bound on medium- and longer-term rates.