Robust Optimal Policies in a Behavioural New Keynesian Model

This paper introduces model uncertainty into a behavioral New Keynesian DSGE framework and derives robust optimal monetary policies. We build a heterogeneous agents DSGE model, where a fraction of agents behave according to some forms of bounded rationality (boundedly rational agents), while the reminder operate on the basis of expectations that are corrected on average (rational agents). We consider two potential mechanisms of expectations formation to generate beliefs. The central bank observes the aggregate economic dynamics, but it ignores the fraction of boundedly rational agents and/or the mechanism they use to form their expectations. Non-Bayesian robust control techniques are then adopted to minimize a welfare loss derived from the second-order approximation of agents’ utilities. We account of model uncertainty considering both commitment and discretion regime.