A Theory of Intrinsic Inflation Persistence

We propose a novel theory of intrinsic inflation persistence by introducing trend inflation and Kimball (1995)-type aggregators of individual differentiated goods and labor in a model with staggered price- and wage-setting. Under nonzero trend inflation, the non-CES (constant elasticity of substitution) aggregator of goods and staggered price-setting give rise to a variable real marginal cost of goods aggregation, which becomes a driver of inflation. This marginal cost consists of an aggregate of the goods' relative prices, which depends on past inflation, thereby generating intrinsic inertia in inflation. Likewise, the non-CES aggregator of labor and staggered wage-setting lead to intrinsic inertia in wage inflation, which enhances the persistence of price inflation. With the theory we show that inflation exhibits a persistent, hump-shaped response to monetary policy shocks. We also demonstrate that lower trend inflation reduces inflation persistence and that a credible disinflation leads to a gradual decline in inflation and a fall in output.