Structural evolution of global plastic life cycle trade: A multilayer network perspective

Abstract

International trade in plastics accounts for 5 % of total merchandise trade and involves all nations in modern society. To explore global plastic life cycle trade, a life cycle-based plastic trade multilayer network (LC-PTMN), including a raw materials layer, a semifinished products layer, a plastic products layer, and a plastic waste layer, is constructed. The structure of the global plastic trade is studied by analyzing each layer in the LC-PTMN from 1990 to 2019. The results reveal that the LC-PTMN has a prominent hierarchical structure and a small-world property, namely, a few countries occupy most trade channels and trade volume. The trade channels and trade volume in the plastic waste layer are the most concentrated. Countries with massive channels have a strong cooperative ability to prompt their trading partners to form close groups. Developing countries in Asia, such as Vietnam and Turkey, have outstanding performance in the LC-PTMN. The major trade flows have distinct geographical patterns, mainly occurring in intra-North American, intra-Asian and North American-Asian networks. Additionally, the community structures of the LC-PTMN have tended to stabilize. Dramatic changes are mainly caused by the merging of European countries with Asian and African countries and the split of North American countries from other countries. These findings will help policy makers encourage plastic sector transformation.