From Taylor's rule to Bernanke's temporary price level targeting

Bernanke's strategies for integrating forward guidance into conventional instrument rules anticipate that effective lower bound (ELB) episodes may become part a regular occurrence and that monetary policy should recognize this likelihood (Bernanke (2017a); Bernanke (2017b)). Bernanke's first proposal is a form of flexible temporary price level targeting (TPLT), in which a lower-for-longer policy path is prescribed through a "shadow rate". This shadow rate accounts for cumulative shortfalls in inflation and output relative to exogenous trends, and the policy rate is kept at the ELB until the joint shortfall is made up. Bernanke's second proposal adds only the cumulative inflation shortfall since the beginning of an ELB episode directly to an otherwise standard Taylor rule. This cumulative shortfall in inflation from the 2 percent objective can be restated in terms of deviations of the price level from a price level target that increases at 2 percent annually. We evaluate the performance of these strategies, which we call Bernanke's TPLT rules, using a small version of the FRB/US model. We then optimize these rules, computing efficient policy frontiers that trace out the best (minimum) obtainable combinations of output and inflation volatility given the effective lower bound constraint on the policy rate. The results suggest that Bernanke's rules give better macroeconomic outcomes than most of the other rules considered in the literature (including Taylor (1993) and Taylor (1999)) by stabilizing inflation and unemployment during severe recessions. Under these TPLT strategies, when the policy rate is made more responsive to shortfalls in inflation, the the likelihood of below-target inflation occurring alongside high unemployment rates decreases. However, the probability of an overheated economy, with temporarily above-target inflation and low unemployment rate, increases