Does urban construction land in China achieve sustainable allocation and utilization?

Building sustainable cities and communities is a key priority of the Sustainable Development Goals. However, the spatial mismatch of construction land (SMCL) poses a significant challenge to sustainable urban development. This paper presents a new framework for measuring the SMCL from the dual perspectives of planning deviation (PD) and economic mismatch (EM). Using a minimum deviation estimation model, a land-comparable correction method, and the extended HK model, this study focused on 285 cities in China from 2002 to 2021. The results revealed that the PD exhibited an "N"-shaped fluctuating trend, reaching a peak of 27.63 km2 in 2011, with the deviation direction generally characterized by over-planning allocation followed by lack of planning allocation. The eastern region had the highest PD, with an annual average of 35.06 km2, followed by the western region. In contrast, the central and northeast regions had relatively low PD. The EM fluctuated in a "W" shape, with an annual average of 0.37. The direction was always dominated by economic over-allocation and complemented by economic under-allocation. There was also heterogeneity in EM across regions. Furthermore, both PD and EM differed considerably between cities by size. In 2021, most cities in China still existed PD or EM, but EM was more widespread and severe. This indicated that SMCL was still a serious issue in China, and there was still a long way to go to achieve the vision of sustainable allocation of construction land. This paper enriches the relevant literature on SMCL and provides a decision-making reference for governments to implement optimal land allocation.