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...

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...

The aim of this paper is to develop a continuous time exchange rate model that allows for heterogeneity of the agents' beliefs, in order to explore non-linearities and possible chaotic behaviour. The theoretical model contains an intrinsic non-linearity that gives rise to a jerk differential...

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

The present complexity approach is based on two assumptions: A1: measurability of deviations of outcomes with respect to reference values; A2 : extension of A1 to multi-set analysis. Complexity is then defined in terms of multi-set deviation compared to single-set ones; an interpretation is...

We incorporate a renewable resource into an overlapping generations model with standard, well-behaved utility and constant returns to scale production functions. Besides being a factor of production the resource serves as a store of value. We characterize dynamics, efficiency and stability of...