We examine global economic dynamics under infinite-horizon learning in a New Keynesian model in which the interest-rate rule is subject to the zero lower bound. As in Evans, Guse and Honkapohja (2008), we find that under normal monetary and fiscal policy the intended steady state is locally but...

We examine global economic dynamics under learning in a New Keynesian model in which the interest-rate rule is subject to the zero lower bound. Under normal monetary and fiscal policy, the intended steady state is locally but not globally stable. Large pessimistic shocks to expectations can lead...

This paper studies the implications for monetary policy of heterogeneous expectations in a New Keynesian model. The assumption of rational expec- tations is replaced with parsimonious forecasting models where agents select between predictors that are underparameterized. In a Misspecification...

We examine existence and stability under learning of sunspot equilibria in a New Keynesian model incorporating inertia. Indeterminacy remains prevalent, stable sunspots abound, and inertia in IS and AS relations do not significantly impact the policy region containing stable sunspots.

Expectations play a central role in modern macroeconomic theories. The econometric learning approach models economic agents as forming expectations by estimating and updating forecasting models in real time. The learning approach provides a stability test for rational expectations and a...

We show that if policy-makers compute the optimal unconstrained interest-rate rule within a Taylor-type class, they may be led to rules that generate indeterminacy and/or instability under learning. This problem is compounded by uncertainty about structural parameters since an optimal rule that...

Forward-looking monetary models with Taylor-type interest rate rules are known to generate indeterminacies, with a potential dependence on extraneous "sunspots," for some structural and policy parameters. We investigate the stability of these solutions under adaptive learning, focusing on...

We study how the use of judgement or "add-factors" in macroeconomic forecasting may disturb the set of equilibrium outcomes when agents learn using recursive methods. We isolate conditions under which new phenomena, which we call exuberance equilibria, can exist in standard macroeconomic...

Using New Keynesian models, we compare Friedman's k-percent money supply rule to optimal interest rate setting, with respect to determinacy, stability under learning and optimality. First we review the recent literature: open-loop interest rate rules are subject to indeterminacy and instability...

We consider optimal monetary policy in New Keynesian models with inertia. First order conditions, which we call the MJB-alternative, are found to improve upon the timeless perspective. The MJB-alternative is shown to be the best possible in the sense that it minimizes policymakers' unconditional...