PURCHASING POWER PARITY IN AFRICAN COUNTRIES: EVIDENCE FROM PANEL SURADF TEST

This study reexamines the validity of long-run purchasing power parity (PPP) hypothesis using a battery of panel unit root tests for 11 developing countries in Africa over the period 1980-2007. Based on the conventional panel unit root tests, we found evidence that the monthly real exchange rates in these countries were mean reverting. By contrast, the series-specific unit root test proposed by Breuer et al. (SURADF) reveals that only six of the 11 RERs series were stationary using the US dollar as reference currency. Additionally, our results reveal that there is stronger evidence of the parity condition with the Rand-based rates than in the other currency-based rates like the US dollar or Euro. We conclude that PPP holds in some, but not all, of the African countries according to the SURADF tests.     

EVIDENCE OF PURCHASING POWER PARITY IN SILVER‐BACKED MEXICO AND INDIA

This paper examines whether the theory of purchasing power parity (PPP) existed between Mexico and India for the period 1886–1910. It finds that despite not having a known trade relationship, PPP did hold. The explanation lies in the fact that these very different countries adhered to the silver standard far longer than most others – India through to 1893 and Mexico until 1905. The economic consequences of this adherence exposed both countries to similar international currency fluctuations that also provoked similar policy reactions within each country.     

PURCHASING POWER PARITY IN AFRICAN COUNTRIES: FURTHER EVIDENCE FROM FOURIER UNIT ROOT TESTS BASED ON LINEAR AND NONLINEAR MODELS

This paper examines the validity of purchasing power parity hypothesis for 33 African countries using recently developed Fourier unit root tests by Christopoulos and León‐Ledesma that account for the existence of multiple breaks in the real exchange rates. The results support the evidence of the PPP in 20 countries, showing that most of the real exchange rates in the selected countries are characterised by linear or nonlinear stationary around multiple temporary mean changes.     

PURCHASING POWER PARITY WITH RANK TESTS FOR NONLINEAR COINTEGRATION IN AFRICAN COUNTRIES

This study applies nonlinear cointegration to assess exchange rates with the corresponding relative prices and aggregate price levels for 20 African countries. We find that a nonparametric rank test has higher power than parametric testing procedures; a true data‐generating process of exchange rate is in fact a stationary nonlinear process. We examine the validity of purchasing power parity (PPP) from the nonparametric nonlinear point of view and provide robust evidence that clearly indicates PPP holds true for these countries. Hence, the long‐run African countries exchange rate adjustments are in equilibrium with the relevant fundamentals as suggested by the PPP hypothesis in a nonlinear way.     

DO AFRICAN COUNTRIES MOVE ASYMMETRICALLY TOWARDS PURCHASING POWER PARITY?

This paper investigates the possibility that the adjustment towards long‐run relative purchasing power parity (PPP) is dependent upon the nature of deviations from PPP that are experienced. While existing studies involving developed and less developed countries often find against PPP having employed linear tests of non‐stationarity or non‐cointegration, we employ a new cointegration test, recently advocated by Enders and Siklos and Enders and Dibooglu, that tests for an asymmetric adjustment towards parity with respect to positive and negative deviations of the real exchange rate from its equilibrium value. Using a sample often African economies with data taken from the post‐Bretton Woods floating exchange rate era, long‐run PPP holds in eight of these cases if an explicit distinction is made between positive and negative deviations. Across the sample, we find variation in the type of asymmetry experienced and the roles played by price and nominal exchange rate adjustment.     

TESTING FOR PURCHASING POWER PARITY AND UNCOVERED INTEREST PARITY IN THE PRESENCE OF MONETARY AND EXCHANGE RATE REGIME SHIFTS

Testing for purchasing power parity (PPP) and uncovered interest parity (UIP) has been the focus of many empirically oriented studies. While these simple economic theories of exchange rate and interest rate determination are theoretically attractive, the empirical support for these equilibrium conditions is at best mixed. Many potential reasons have been cited in the literature for the failure of such studies, ranging from market imperfections to inappropriate modelling strategies. The current state‐of‐the‐art procedure involves testing for two cointegrating vectors in a multivariate error correction model which may be economically identified as the PPP and UIP relations. However, such a procedure does not account for policy regime shifts which distort the underlying PPP and UIP relations. In this paper, a Markov‐switching vector error correction model (VECM) is considered for time series data in which monetary and exchange rate regime shifts are known to be present. Weak evidence in favour of PPP and UIP is established in a standard linear VECM, although the residuals of this model indicate that it is inappropriate in terms of functional form. The Markov‐switching VECM, however, provides convincing evidence in favour of both the PPP and UIP relations and a marked improvement in the residual distributions.     

TAKING THE PUZZLE OUT OF THE PURCHASING POWER PARITY PUZZLE: AN APPLICATION IN RESPECT OF SOUTH AFRICA

This paper discusses two versions of the purchasing power parity puzzle. It presents the results of nonlinearity and nonstationarity tests in respect of the real exchange rates of the rand. It is found that the rand real exchange rate behaviour tends to be nonlinear and stationary in a majority of cases in the sample. This suggests that for the majority of the currencies in the sample, the real exchange rates of the rand are mean‐reverting, implying that the purchasing power parity relation holds in a nonlinear manner.     

IMPLICATIONS OF REAL EXCHANGE RATE MISALIGNMENT IN DEVELOPING COUNTRIES: THEORY,EMPIRICAL EVIDENCE AND APPLICATION TO GROWTH PERFORMANCE IN ZIMBABWE

The influence of exchange rate signals in an economy is very powerful and often pervasive. Moreover, sustained real exchange rate overvaluation will, by distorting resource allocation away from productive activities, eventually lead to drastic adjustments of relative prices and reduction of aggregate economic growth. However, the direct theoretical and empirical link between exchange rate misalignment and macroeconomic indicators still remains to be fully understood. Nonetheless, empirical studies continue to make attempts to understand this relationship by exploring relationships that incorporate different measures of exchange rate misalignment in traditional growth regression models. Based on a behavioural equilibrium exchange rate derived measure exchange rate misalignment, this paper presents an empirical analysis of the relationship between real gross domestic product growth and real exchange rate misalignment for Zimbabwe. After controlling for other structural and policy variables, the main findings demonstrate that exchange rate misalignment exerts a negative and highly statistically significant impact on growth. Overall, the results lend support to the hypothesis that chronic real exchange rate overvaluation was a key fundamental behind the post‐2000 economic growth contraction in Zimbabwe.