銅供給構造の変遷の分析

–企業ネットワークからのアプローチ–

抄録

Global demands for minerals keep increasing and securing the stable supply remains huge concern for us. In addition, the supply chain structure has dramatically changed during the last decade or two and this also affects our resource security. In this paper, we chose the copper industry as a case study and applied social network analysis (SNA) to corporate ownership information and international trade data. With the help of SNA, the change of ownership structure behind the physical/monetary flows of copper was visualized and analyzed quantitatively. From the analysis for ownership information, we found out mining majors had increased their presence in the industry, while Japanese companies changed their approach and increase their relationship to the whole structure of the industry, which will contribute to stabilize Japanese copper raw material supply. Combining both ownership and trade flow analysis, China also increased its presence in the trade flows. However, in the case of ownership network, their presence as a group is not as large as it is in the case of trade flows. However, PageRank showed that the State of China is already one of the biggest entity in the industry, which might reflect its resource policy.