Dynamic Pricing and Imperfect Common Knowledge

This paper introduces private information into the dynamic pricing decision of firms in an otherwise standard new Keynesian model by adding an idiosyncratic component to firms’ marginal costs. The model can then replicate two stylised facts about price changes: aggregate inflation responds gradually and with inertia to shocks, while at the same time price changes of individual goods can be quite large. The inertial behaviour of inflation is driven by privately informed firms strategically ‘herding’ on the public information contained in the observations of lagged aggregate variables. The model also matches the average duration between price changes found in the data and it nests the standard new Keynesian Phillips curve as a special case. To solve the model, the paper derives an algorithm for solving a class of dynamic models with higher-order expectations.