Guneratne Wickremasinghe

Abstract: This article examines mean-reversion of real exchange rates of Papua New Guinea (PNG), which is the crucial condition for purchasing power parity (PPP) to hold. Taking a departure from the most previous studies, we used six panel unit root tests to investigate the empirical validity of the PPP hypothesis to PNG. Both the preliminary analysis performed by examining time series plots of real exchange rates and the results of the panel unit root tests indicate that the PPP does not hold for PNG. These results may be attributed to frictions, such as transportations costs, prevailing in international trade that lead PPP to follow a nonlinear stochastic process. This issue will be investigated in future research.

Abstract: This study examines the validity of the Purchasing Power Parity (PPP) hypothesis to a developing country such as Papua New Guinea during the floating exchange rate regime. The empirical analysis was performed using recently developed Ng-Perron (2001) unit root tests which are more powerful than widely-used Dickey-Fuller-type unit roots. Ng-Perron test results indicate that the four real exchange rates (Australian dollar, Japanese yen, UK pound and US dollar) are non-stationary. Further, a comparison of exchange rates that should prevail under the PPP with actual exchange rates provides evidence that the kina was undervalued during the sample period. These results are inconsistent with the PPP and have implications for policy makers and participants of the foreign exchange market of Papua New Guinea.