現代ポートフォリオ理論から見た資源メジャーの経営戦略

抄録

Mineral prices hit their ceilings and started fluctuating. It forced resource-related companies to reassess their assets. In order to secure the stable supply of resources, it is important for Japan, which is a resource-importing country, to keep an eye on the changes in strategies of resource-related companies, especially mining giants that dominate the global production of various minerals. There are some studies focusing only on risk management at an individual mine level and fluctuation in mineral prices, but few studies focus on asset management of the mining giants as an entity. The purpose of this paper is to analyze and understand the asset management strategies of the mining giants. All assets of the giants, such as mines, smelters and refineries are considered as risky assets, calculating the optimal portfolio under the “Modern Portfolio Theory”. By comparing the derived optimal portfolio with the actual one, we conclude that the mining giants' asset management strategies are almost optimal. We also found out which asset will be on sale from each company, which can be useful for Japanese companies increasing the share in overseas mines.