In this paper we investigate the nature of rational expectations equilibria for economic epidemiological models. Unlike mathematical epidemiological models, economic epidemiological models can produce regions of indeterminacy or instability around the endemic steady states. We consider SI, SIS,...

Increasing returns to scale and firms' market power are two potential sources of sunspot expectations in neoclassical models. We show that in New Keynesian models, returns to scale and market power can have fundamentally different implications for broad macroeconomic issues, including...

A challenge to models of equilibrium indeterminacy based on increasing returns is that required increasing returns for generating indeterminacy can be implausibly large and rise quickly with the relative risk aversion in labor. We show that unsynchronized wage adjustment via a relative wage...

We show that, with endogenous investment, virtually all monetary policy rules that set a nominal interest rate in response solely to expected future inflation induce real indeterminacy in models with (i) staggered prices, (ii) staggered prices and staggered wages, and (iii) staggered prices,...

In sticky price models with endogenous investment, virtually all monetary policy rules that set a nominal interest rate in response solely to future inflation induce real indeterminacy of equilibrium. Applying the Samuelson-Farebrother conditions, we obtain a necessary and sufficient condition...

In this paper, we investigate the nature of rational expectations equilibria for economic epidemiological models. Unlike mathematical epidemiological models, economic epidemiological models can produce regions of indeterminacy or instability around the endemic steady state. We consider SI, SIS,...