This paper employs recently developed techniques to test the strong version of purchasing power parity (PPP) for a panel of post-Bretton Woods data. The study compares results using fully modified and dynamic ordinary least squares (OLS) approaches, strongly rejecting the hypothesis of strong PPP. A new between-dimension dynamic OLS estimator is introduced, and it is found that the between-dimension fully modified OLS (FMOLS) and dynamic OLS (DOLS) estimates of the long-run deviation from PPP are larger than the corresponding within-dimension estimates. The paper also discusses the mixed findings in panel unit root studies and attempts to reconcile them with the results of this study. The results indicate that the failure of strong PPP is pervasive in the post-Bretton Woods period, not driven by a few countries. The study uses various estimators, including within-dimension and between-dimension FMOLS and DOLS, to test the cointegration vector and the null hypothesis of no cointegration. The findings suggest that the between-dimension estimators provide a more accurate representation of the average long-run relationship between nominal exchange rates and aggregate price ratios.This paper employs recently developed techniques to test the strong version of purchasing power parity (PPP) for a panel of post-Bretton Woods data. The study compares results using fully modified and dynamic ordinary least squares (OLS) approaches, strongly rejecting the hypothesis of strong PPP. A new between-dimension dynamic OLS estimator is introduced, and it is found that the between-dimension fully modified OLS (FMOLS) and dynamic OLS (DOLS) estimates of the long-run deviation from PPP are larger than the corresponding within-dimension estimates. The paper also discusses the mixed findings in panel unit root studies and attempts to reconcile them with the results of this study. The results indicate that the failure of strong PPP is pervasive in the post-Bretton Woods period, not driven by a few countries. The study uses various estimators, including within-dimension and between-dimension FMOLS and DOLS, to test the cointegration vector and the null hypothesis of no cointegration. The findings suggest that the between-dimension estimators provide a more accurate representation of the average long-run relationship between nominal exchange rates and aggregate price ratios.