Measuring external oil supply risk: A modified diversification index with country risk and potential oil exports

External oil supply risk is an important aspect of energy security and oil import diversification is viewed as one of the most effective measures to reduce supply risk. By using the diversification index approach, this research attempts to assess external oil supply risks of oil importers with consideration of two key factors associated with oil suppliers, country risk and potential oil exports capacity. The former can be used to reflect the oil...