Double Inertia, Taylor Rules, and Monetary Policy Gradualism

In recent decades, an empirically estimated double-inertial rule fits the path of changes in the federal funds rate better than a standard inertial Taylor rule. Inertial Taylor rules aim to capture monetary policy gradualism via slow adjustments in the level of the policy rate. Double-inertial rules build on this specification by also gradually adjusting the pace of change in the policy rate. Because a double-inertial rule explains more than twice the variation of changes in the policy rate than its standard inertial counterpart, we argue that practitioners should consider a double-inertial rule when characterizing U.S. monetary policy.