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.

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...