Central banks' macroeconomic projections and learning

We study the impact of the publication of central banks� macroeconomic projections on the dynamic properties of an economy where (i) private agents have incomplete information and form their expectations using recursive learning algorithms; (ii) the short-term nominal interest rate is set as a linear function of the deviations of inflation and real output from their target level; and (iii) the central bank, ignoring the exact mechanism used by private agents to form expectations, assumes that it can be reasonably approximated by perfect rationality and releases macroeconomic projections consistent with this assumption. The set of macroeconomic projections released by the central bank crucially affects the results in terms of stability of the equilibrium and speed of convergence of the learning process. In particular, while the publication of inflation and output gap projections enlarges the set of interest rate rules associated with stable equilibria and helps agents to learn faster, the announcement of the interest rate path exerts the opposite effect. In the latter case, in order to stabilize expectations and to speed up the learning process the response of the policy instrument to inflation should be stronger than when there is no announcement.