Policy Rules and Economic Performance

Debates about the conduct of monetary policy have evolved over time from “rules versus discretion” to “policy rules versus constrained discretion.” We propose a metric to evaluate monetary policy rules that are consistent with constrained discretion by calculating quadratic loss ratios, the (inflation plus unemployment) loss in high deviations periods divided by the loss in low deviations periods, with policy rules with higher loss ratios preferred to rules with lower loss ratios. The central results of the paper are (1) economic performance is better in periods of low deviations from policy rule prescriptions than in periods of high deviations from policy rule prescriptions for the vast majority of rules, and (2) rules with larger coefficients on the inflation gap than on the output gap are preferred to rules with larger coefficients on the output gap than on the inflation gap. These results are robust to policy lags between one and two years, different weights on inflation loss than on unemployment loss, various definitions of high and low deviations periods, fixed and time varying neutral real interest rates, fixed and time-varying inflation targets, and measuring economic slack by either the output gap or the unemployment gap. We conclude that (1) the Fed should “constrain” constrained discretion by following a rule that responds more strongly to inflation gaps than to output gaps and (2) this type of rule should be added to the Fed's semi-annual Monetary Policy Report.