Ntim, Collins G.; Opong, Kwaku K.; Danbolt, Jo - In: The African Finance Journal 9 (2007) 2, pp. 1-25
robust non-parametric variance-ratios test in addition to its parametric alternative. The main finding is that stock returns … as the choice of dataset. Consistent with prior studies, the results of the parametric variance-ratios test are ambiguous …