Fractional Cointegration Analysis of Long Term International Interest Rates

DeGennaro, Kunkel, and Lee (1994) studied the long run dynamics of a system of long term interest rates of five industrialized countries by means of sophisticated cointegration methods. They found little evidence in support of the cointegration hypothesis, thus concluding that a separate set of fundamentals drives the dynamics of each of the individual long term interest rate series. In this study, we extend their analysis by exploring the possibility of very slow mean reverting dynamics (fractional cointegration) in the system of the five long term interest rates. We use the GPH test as our testing methodology for fractional integration and cointegration. Through rigorous investigation of the full system of the five long term interest rate series and its various subsystems, we provide evidence that the error correction term follows a fractionally integrated process with long memory, that is, it is mean reverting, though not covariance stationary. Despite significant persistence in the short run, a shock to the system of long term interest rates eventually dissipates so that an equilibrium relationship prevails in the long run.