Inflation Dynamics with a Generalized Lucas Phillips Curve

(December 2025 big revision) I add lagged expectations to a Lucas Phillips curve, in the style of Mankiw and Reis. The resulting model is initially unstable, so that inflation builds over time in response to a shock. In the long run though, inflation is stable. This change solves the puzzle that in the standard textbook model inflation and output both rise in response to higher interest rates, allowing at most a single initial downward jump. The half of the last draft dealing with the standard model is now split off into “New-Keynesian Inflation Control is Equilibrium Selection.” Read the paper>. Computer program>