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...

A general framework is described specifying how boundedly rational decision makers generate their choices. Starting from a "Master Module" which keeps an inventory of previously successful and unsuccessful routines several submodules can be called forth which either allow one to adjust behavior...