Cointegration of price measures: Evidence from the G-7

This study addresses index-dependency of empirical results associated with the purchasing power parity (PPP) relationship. Using four key price indices involving the G-7 nations, empirical tests for long-run co-movement are conducted. A test for linear restrictions is imposed. The speeds of adjustment are calculated for statistically significant linear combinations. The speed of the short-run response to disequilibrium differs both within and across countries. The seven-country average reveals that the CPI has the quickest recovery response to a one-time disturbance. The findings suggest that PPP results are not dependent upon the choice of index when an explicit set of indices is cointegrated.(JEL F3)