A breakthrough in macro-scale circularity and eco-efficiency assessment: A case study of OECD countries.

Countries' circularity performance and CO emissions should be addressed as a part of the UN net-zero Sustainable Development Goals (SDGs) 2030. Macro-scale circularity assessment is regarded as a helpful tool for tracking and adjusting nations' progress toward the sustainable Circular Economy (CE) and SDGs. However, practical frameworks are required to address the shortage of real-world circularity assessments at the macro level. The establishment of CE benchmarks is also essential to enhance circularity in less sustainable nations. Further, monitoring the extent to which nations' circularity activities are sustainable and in line with the SDGs is an area that lacks sufficient practical research. The current research aims to develop a macro-level framework and benchmarks for national sustainable circularity assessments. Methodologically, we develop a dynamic network data envelopment analysis (DN-DEA) framework for multi-period circularity and eco-efficiency assessment of OECD countries. To do so, we incorporate dual-role and bidirectional carryovers in our macro-scale framework. From a managerial perspective, we conduct a novel comparative analysis of the circularity and eco-efficiency of the nations to monitor macro-scale sustainable CE trends. Research results reveal a significant performance disparity in circularity, eco-efficiency, and benchmarking patterns. Accordingly, circularly efficient nations cannot necessarily be considered eco-friendly and sustainable. Although Germany (as a superior circular nation) can be regarded as a circularity benchmark, it cannot serve as an eco-efficiency benchmark for less eco-efficient nations. Hence, the new method allows decision-makers not only to identify the nations' circularity outcome but also to distinguish sustainable nations from less sustainable ones. This, on the one hand, provides policymakers with a multi-faceted sustainability analysis, beyond the previous unidimensional analysis. On the other, it proposes improvement benchmarks for planning and regulating nations' future circularity in line with real sustainability goals. The capabilities of our innovative approach are demonstrated in the case study.