World rare earths trade network: Patterns, relations and role characteristics

Due to the uneven geographical distribution of rare earths (RE), most countries obtain RE on the international market. Trade patterns and trading countries' role characteristics are two important aspects to understand the current status of world RE trade and furthermore to formulate RE trade policies for each trading country. A complex network theory is adopted to analyze the world RE trade based on the trading data of 2011-2015. The results show that world RE trade favors a tendency towards collectivization since 146 trading countries only form three trade communities. Of these communities, the one headed by the United States, China, Japan, and Germany, has the largest clustering coefficient and has the greatest effect on the world RE trade. Moreover, the average path length valued by 2.294 steps in the network shows that the trading countries are quite close to each other, i.e., building up trade relations between any two countries needs an average path length of only 2.294 steps. Based on the role characteristics analysis of the degree centrality, strength centrality, closeness centrality, eigenvector centrality, and betweenness centrality, our study characterized the competing and complementary relationships between the major trading countries. Finally, the policy implications for different trading countries are proposed. (C) 2016 Elsevier Ltd. All rights reserved.