Robust Real Rate Rules

Central banks wish to avoid self‐fulfilling fluctuations. Interest rate rules with a unit response to real rates achieve this under the weakest possible assumptions about the behavior of households and firms. They are robust to household heterogeneity, hand‐to‐mouth consumers, non‐rational household or firm expectations, active fiscal policy, and to any form of intertemporal or nominal‐real links. They are easy to employ in practice, using inflation‐protected bonds to infer real rates. With a time‐varying short‐term inflation target, they can implement an arbitrary inflation path, including optimal policy. This provides a way to translate policy makers' desired path for inflation into one for nominal rates. U.S. Federal Reserve behavior is remarkably close to that predicted by a real rate rule, given the desired inflation path of U.S. monetary policy makers. Real rate rules work thanks to the key role played by the Fisher equation in monetary transmission.