Indeterminacy in a Forward-Looking Regime-Switching Model

This paper is about the properties of Markov-switching rational expectations (MSRE) models. We present a simple monetary policy model that switches between two regimes with known transition probabilities. The first regime, treated in isolation, has a unique determinate rational expectations equilibrium, and the second contains a set of indeterminate sunspot equilibria. We show that the Markov switching model, which randomizes between these two regimes, may contain a continuum of indeterminate equilibria. We provide examples of stationary sunspot equilibria and bounded sunspot equilibria, which exist even when the MSRE model satisfies a generalized Taylor principle. Our result suggests that it may be more difficult to rule out nonfundamental equilibria in MRSE models than in the single-regime case where the Taylor principle is known to guarantee local uniqueness