Credibility and Monetary Policy

This paper investigates the ability of monetary policy rules to coordinate private agents’ expectations when the enforcement of rules is limited. We show that limited enforcement precludes diverging inflation paths ensuring that nominal variables remain bounded in equilibrium. When applied to Taylor rules, this makes the Taylor principle necessary and sufficient for price determinacy when agents expect a Taylor rule. However, limited enforcement also allows agents to rationally anticipate multiple policies and we show that, in general, there is no policy rule able to recoordinate any private agents’ belief on that rule. We finally provide conditions under which such recoordination may take place