A testing of the purchasing power parity hypothesis using a vector autoregressive model

The paper examines the hypothesis of purchasing power parity relations and the hypothesis of interest rates parity relations between the Japanese yen and the US dollar in a four-dimensional VAR (4-VAR) model, using the statistical technique developed by Johansen and Juselius (1992). The paper demonstrates that the so-called symmetry restriction on the PPP relationship holds not in a 3-VAR model but in the 4-VAR model, which indicates that a correct specification of the sampling distribution of data is important. The interest rates parity relation also holds in the 4-VAR model. The one-step prediction based on the ECM representation with such long-run relations outperforms the random walk model. These results are similar to those under the exchange rate control period (January 1974 to December 1980), which support the inclusion of this period in a whole sample period (January 1974 to December 2001). © Springer-Verlag 2004.