We develop a simple model of the exchange rate in which agents optimize their portfolio and use different forecasting rules. They check the profitability of these rules ex post and select the more profitable one. This model produces two kinds of equilibria, a fundamental and a bubble one. In a...

In this paper we model how the existence of different beliefs about the underlying fundamental value of a currency affects the dynamics of the exchange rate. We find that a divergence of beliefs creates the potential for waves of optimism and pessimism that alternate in an unpredictable way....

We develop a behavioral macroeconomic model in which agents use simple but biased rules to forecast future output and inflation. This model generates endogenous waves of optimism and pessimism (quot;Animal Spiritsquot;) that are generated by the correlation of biased beliefs. We contrast the...