Spatial and temporal disparity of the in-use steel stock for China

The in-use steel stock is an important indicator of urban metabolism. However, there is a big gap in the in-use steel stock level among different regions because of diverse driving factors and the mechanism of how the factors act on the in-use steel stock. This strongly aggravated the difficulty of accounting in-use steel stock. To identify the comprehensive disparity, this paper took China's provinces as the empirical context and established a hybrid accounting model framework by considering the unique characteristics for the downstream steel-using sectors. The results show that China's per capita in-use steel stock have increased by 1.96 times from 2002-2016, reaching 3.65 ton/cap in 2016. Therein, the building sector always contributes more than 50 % of the increase. Based on the change of per capita in-use steel stock and socio-economic factors, Chinese provinces can be divided into three clusters. The driving factors have different effects on the per capita in-use steel stock in three types of provinces. For example, an increase of 1 % in the urbanization rate would increase the per capita in-use steel stock for the infrastructure sector by 0.55%o2.69% in these three types of provinces. In addition, foreign direct investment, the aging population and per capita income are the main factors affecting the in-use steel stock. From 2021-2035, it would be the peak period of scrap production in the building sector. The government is suggested to implement fiscal preferential policies to achieve effective recycling of scrap.