September 1, 2004
Using parametric return autocorrelation tests and non parametric variance ratio statistics show that the UK and US short-term interest rates are unit root processes with significant mean reverting components. Congruent with this empirical evidence, we develop a new continuous time term structure model which assumes that the dynamics of the instantaneous interest rate are given by the joint effect of a (stationary) mean reverting component and a (nonstationary) martingale component. We provide a closed-form solution for the equilibrium yield curve when the temporary component is modelled as an Ornstein-Uhlenbeck process and the permanent component is modelled as an Arithmetic Brownian motion process.
J.E.L classification codes: C20, E43, G12
Keywords:C20, E43, G12