International copper flow network: A blockmodel analysis

Industrial Ecology is looking for new tools to combine social and economic dimensions with the already well developed physical flow analysis of the human economic system. This article introduces a tool from social network analysis as complementary to the existing multilevel substance flow analysis by exploring the concept of space and region, in which substance flows happen. We use the blockmodel from network analysis in the characterization of the multilevel anthropogenic copper cycle to group countries according to their structural equivalence in the international trade networks related to copper, instead of using a priori aggregation standards, such as geographical proximity, GDP per capita, or widely accepted classification of industrial/developing countries. This approach depicts the patterns of material movement through trade, which reflects the inherent structure of the world system regarding copper production and consumption. The results highlight the uneven distribution of global copper stocks and flows across countries in the middle 1990s, and illustrate the core-peripheral structure among different country groups, in which a close interconnected core exist with sparse ties to peripheral groups, and copper are flowing from the peripheral to the core in terms of net flows. (c) 2006 Elsevier B.V. All rights reserved.