Performance analysis of China's regional circular economy from the perspective of circular structure

China's Industry 4.0 plan, also known as “Made-in-China 2025″, emphasizes the development of circular economy (CE) to improve the efficiency of resource recycling. The main goal of a CE is to minimize resource input, maximize economic output, and lessen the influence on the natural environment. To achieve the goal of developing CE in the context of Industry 4.0, China's government has issued a series of supporting policies. This paper proposes a closed-loop network data envelopment analysis model to appraise and investigate the performance of China's regional industrial CE systems and provide suggestions for improving industrial CE performance in China. The proposed model takes the recycling of resources in the system into account. Then, the proposed model is employed to analyze the performance of industrial CE systems at the province-level in China. The evidence has reached some key findings. First, the performance of China's industrial CE systems did not change much during the period from 2013 to 2017, but the average efficiency was low. Second, the production efficiency (PE) of each province's industrial CE system was higher than the pollution treatment efficiency (PTE). Third, the development trends of the average PE and average PTE of industrial CE systems are the same, first showing a decrease and then an increase. Fourth, only 10 out of 29 industrial CE systems performed well during the study period; the remaining CE systems need to improve in terms of production efficiency or pollution control efficiency, or both.