Les modèles de taux de change. Équilibre de long terme, dynamique et hystérèse

Predicting exchange rates remains a tricky issue for economists. In spite of a theoretical consistent framework, macroeconomic models fail to beat random walk models and market expectations have not predictive power. The article addresses some problems of exchange rate macroeconomic modelling. The first part discusses theories of long run exchange rate equilibrium (FEER, DEER, BEER and NATREX). The second part presents a small macroeconomic model of exchange rates dynamics; it consider several modelling alternatives ?' monetary policy specification, price-wages loop, portfolio and patrimonial effects ?' and analyse their impacts on long run and dynamic properties. The third part introduces explicitly fiscal policy specifications. Last, the fourth part gives an example of a model with hysteresis, where temporary shocks influence the long-term exchange rate equilibrium.