Testing Random Walk Behavior of Currency Returns for African Countries

This paper investigates the random walk behavior of currency returns for 15 African countries, namely, Ethiopia, Gambia, Ghana, Kenya, Madagascar, Mali, Mauritius, Morocco, Nigeria, Rwanda, Sierra Leone, South Africa, Tanzania, Uganda, and Zambia. In particular, the paper applies the nonparametric variance-ratio tests proposed by Wright (2000). The two important findings that emerge from this study are: first, contrary to most of the earlier studies on this issue, this study finds evidence against random walk behavior for currency returns of all sample countries; second, the rejection of the null hypothesis of random walk suggests that shocks to the currency return series are temporary. This finding implies that foreign exchange markets of the sample countries are inefficient and present opportunities to aggressive investors who seek high rates of return irrespective of the level of risk involved