This paper reexamines the implications of the zero lower bound on interest rates for monetary policy and the optimal choice of steady-state inflation in light of the experience of the recent global recession. There are two main findings. First, the zero lower bound did not materially contribute to the sharp declines in output in the United States and many other economies through the end of 2008, but it is a significant factor slowing recovery. Model simulations imply that an additional 4 percentage points of rate cuts would have kept the unemployment rate from rising as much as it has and would bring the unemployment and inflation rates more quickly to steady-state values, but the zero bound precludes these actions. This inability to lower interest rates comes at the cost of $1.7 trillion of foregone output over four years. Second, if recent events are a harbinger of a significantly more adverse macroeconomic climate than experienced over the preceding two decades, then a 2 percent steady-state inflation rate may provide an inadequate buffer to keep the zero bound from having noticeable deleterious effects on the macroeconomy assuming the central bank follows the standard Taylor Rule. In such an adverse environment, stronger systematic countercyclical fiscal policy and/or alternative monetary policy strategies can mitigate the harmful effects of the zero bound with a 2 percent inflation target. However, even with such policies, an inflation target of 1 percent or lower could entail significant costs in terms of macroeconomic volatility.
C. Williams, John. 2009. “Heeding Daedalus: Optimal Inflation and the Zero Lower Bound,” Federal Reserve Bank of San Francisco Working Paper 2009-23. Available at https://doi.org/10.24148/wp2009-23