A Theory of Dynamic Inflation Targets

Should central banks' inflation targets remain set in stone? We study a dynamic mechanism design problem between a government and a central bank. The central bank has persistent private information about structural shocks. Firms learn the state from the central bank's reports and form inflation expectations. A dynamic inflation target implements the full-information commitment allocation. The central bank is delegated the authority to adjust the target's level and flexibility one period in advance. A declining natural interest rate and a flattening Phillips curve imply opposite optimal target adjustments. Our results speak to practical policy questions of inflation target design.