An empirical examination of long-run purchasing power parity using cointegration techniques

This paper presents an empirical analysis of long-run purchasing power parity (PPP) for five major exchange rates using recently developed econometric techniques on the cointegration of economic time series. Our empirical results are extremely unfavourable to the PPP hypothesis as a long-run equilibrium condition, even with an allowance made for measurement error and/or tranportation costs. In particular, we are unable to reject the hypothesis of non-cointegration of the exchange rate and relative prices for any of the countries concerned. Far from finding a stable, long-run proportionality between exchange rates and relative prices, our results therefore suggest that they tend to drift apart without bound.