Nonlinear exchange rate dynamics under stochastic official intervention

Many studies employ non-linear models to explain or forecast the exchange rate and find their superiority. This article builds an exchange rate model of managed float under conditional official intervention. In the model, the government minimizes social loss through a trade-off between targeting the exchange rate and lowering intervention costs. We obtain an endogenous threshold model and derive an analytical solution of the exchange rate stochastic interventions. The implication of a managed float causing a lower volatility of the exchange rate has been found by past empirical studies. Our model provides not only a justification for the central banks' conditional interventions but also a rationale for the use of regime-switching models of two states (intervention vs. non-intervention) in the empirical studies of exchange rates.

► A trade-off lies between targeting the exchange rate and lowering intervention costs. ► Central bank's optimization implies an endogenous threshold model. ► Central banks intervene only for big departures of the exchange rate from its target. ► The managed float model implies a honeymoon effect.