Term structure and interest differentials as predictors of future inflation changes and inflation differentials

The paper tests the unbiasedness of interest differentials and term structure as predictors of inflation differentials and inflation changes, respectively, using three-, six- and twelve-month maturities in eight major industrial countries over the period 1981-1992. The first hypothesis requires rational expectations (RE) and equality of ex-ante real interest rates, which in turn holds only in the presence of uncovered interest parity (UIP) and ex-ante purchasing power parity (PPP). The second is correct if, in addition to RE, the Fisher hypothesis and constancy of ex-ante real rates are satisfied. The empirical results lead to the rejection of both null hypotheses, although interest differentials and term structure do appear to be relatively useful for forecasting purposes. In particular, the interest differential model performs better than simple ARMA models at the shortest end of the maturity spectrum in out-of-sample forecasting.