Characteristics of the global copper raw materials and scrap trade systems and the policy impacts of China's import ban

Copper raw materials (CRM) and copper waste and scrap (CWS) are the two main sources of copper manufactured products. Due to the uneven geographical distribution of copper production and consumption, international CRM and CWS trade developed. However, no study has explored the complicated interdependencies between CRM trade and CWS trade or investigated the characteristics of this multiplex trade system. This study uses trade records from 1988 to 2017 to construct multiplex trade networks: a global CRM trade network and a global CWS trade network. The evolution of copper trade from 1988 to 2017 is reviewed, and the intricate relationships in the multiplex trade network are identified. It is found that CWS trade has a highly positive correlation with CRM trade, but there are obvious differences between CWS trade and CRM trade in the multilateral trade structure. Multilateral trade structures driven by core exporting countries and core importing countries are prominent in CRM trade and CWS trade, respectively. In addition, the impacts of China's restrictive policies on the multiplex trade system are analyzed. The results provide policy implications for countries regarding copper resource security strategies and safeguarding the multiplex trading system.