This paper estimates a New Keynesian model extended to include heterogeneous expectations, to revisit the evidence that postwar US macroeconomic data can be explained as the outcome of passive monetary policy, indeterminacy, and sunspot-driven fluctuations in the pre-1979 sample, with a switch...

We consider the stability under adaptive learning of the complete set of solutions to the model when . In addition to the fundamentals solution, the literature describes both finite-state Markov sunspot solutions, satisfying a resonant frequency condition, and autoregressive solutions depending...