While the economy shows signs of strength, the recovery remains tepid relative to economic upswings following deep recessions of the past. This weakness has occurred despite an aggressive monetary response by the Federal Reserve which has adopted even unconventional tools to reduce long term...

We examine the behavior, determinants, and implications of the equilibrium level of the real federal funds rate, defined as the rate consistent with full employment and stable inflation in the medium term. We draw three main conclusions. First, the uncertainty around the equilibrium rate is...