Expectations and the Neutrality of Interest Rates

April 24 2024. (Rewrite).  The paper>

Abstract: Our central banks set interest rates, and do not even pretend to control money supplies. How do interest rates affect inflation? We finally have a complete economic theory of inflation under interest rate targets and unconstrained liquidity. Its long-run properties mirror those of monetary theory: Inflation can be stable and determinate under interest rate targets, including a peg, analogous to a k-percent rule.

Uncomfortably, stability means that higher interest rates eventually raise inflation, just as higher money growth eventually raises inflation. Sticky prices generate some short-run non-neutrality: Higher nominal interest rates can raise real rates and lower output. A model in which higher nominal interest rates temporarily lower inflation, without a change in fiscal policy, is a harder task. I exhibit one such model, but it paints a more limited picture than standard beliefs. Generically, without a change in fiscal policy, monetary policy can only move inflation from one time to another.

The last decade has provided a near-ideal set of natural experiments to distinguish the principal theories of inflation. Inflation did not show spirals or indeterminacies at the long zero bound. The large monetary-fiscal expansion of the covid era produced a temporary spurt of inflation. The same money unleashed in quantitative easing had no such effect.

This paper resulted from a talk at the  “Foundations of Monetary Policy” conference celebrating 50 years since the publication of ``Expectations and the Neutrality of Money,'' Federal Reserve Bank of Minneapolis, September 2022. Slides Video of my presentation at the Hoover Economics Policy Working group, Dec 14 2022. Programs (updated 4/17/2024).