Although the null hypothesis of homogeneity (as well as of a unit coefficient) in the cointegration
relationship is always rejected for the overall panel set of GCC countries in our monthly data set, it holds
for some specific country pairings. For instance, it is possible to see that the null of homogeneity for bi, that
is the similarity in the responses of stock markets to changes in oil prices, is not rejected for the couple
Bahrain-Oman. Thus, despite the several common characteristics and economic links between GCC
countries, their stock markets do not have similar sensitivities to oil price changes. Finally, our results
suggest that GCC markets have the potential to yield different stock returns and are therefore good
candidates for regional portfolio diversification.