We study whether the source of uncertainty shocks matters for optimal monetary policy, focusing on productivity and cost-push uncertainty shocks. Although both shocks deliver similar macroeconomic dynamics under an empirical Taylor rule, they generate very different dynamics under optimal...

This paper revisits the paradox of flexibility, i.e., the result that, in a liquidity trap, greater price flexibility amplifies output volatility in response to negative demand shocks. We argue this paradox is the consequence of a failure of standard models to correctly characterize monetary...