Threshold effects in cointegrating relationships

In this paper we introduce threshold type nonlinearities within a single equation cointegrating regression model and propose a testing procedure for testing the null hypothesis of linear cointegration versus cointegration with threshold effects. Our framework allows the modelling of long run equilibrium relationships that may switch according to the magnitude of a threshold variable assumed to be stationary and ergodic and thus constitutes an attempt to deal econometrically with the potential presence of multiple equilibria. The framework is flexible enough to accomodate regressor endogeneity and serial correlation.