We develop a simple model of the foreign exchange market 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...

We analyse the workings of a simple non-lnear exchange rate model in which agents hold different beliefs about the underlying model. We destinguish between "chartists" and fundamentalists". The non-linearities in the model originate from transactions costs and from the existence of non-linear...

In this paper we develop a model of the exchange rate. The existence of transactions costs introduces an important non-linearity. Agents have different beliefs about the future exchange rate. We show that this simple model creates great complexity in the market which is characterised by the fact...