This paper studies decision making by agents who value optimism, but are unsure of their environment. As in Brunnermeier and Parker (2005), an agent’s optimism is assumed to be tempered by the decision costs it imposes. As in Hansen and Sargent (2008), an agent’s uncertainty about his...

This article studies a version of Obstfeld's (Journal of International Economics 43 (1997), 61-77) "escape clause" model. The model is calibrated to produce three rational expectations equilibria. Two of these equilibria are E-stable and one is unstable. Dynamics are introduced by assuming that...

We show in a simple monetary model that the learning dynamics do not converge to the rational expectations monetary steady state. We then show it is necessary to restrict the learning rule to obtain convergence. We derive an upper bound on the gain parameter in the learning rule, based on...