Does the “Zero-Waste City” Policy Improve Urban Land Green Use Efficiency? Evidence from China

Waste accumulation and land carrying pressure are common sustainability challenges in urbanization, making the improvement of urban land green use efficiency (ULGUE) a key issue. Using panel data from 278 Chinese cities over 2008–2023, this study treats zero-waste city pilots as a quasi-natural experiment and constructs a difference-in-differences model, measuring ULGUE via a super-efficiency slacks-based measure–Global Malmquist–Luenberger (Super-SBM-GML) model under variable returns to scale. The results show that zero-waste city construction significantly and robustly improves ULGUE. Mechanism analysis shows that zero-waste city construction improves ULGUE mainly by optimizing the waste treatment structure, promoting green technological innovation, and facilitating the development of green industries. Heterogeneity analysis shows that the promoting effect is stronger in eastern regions, key environmental protection cities, old industrial base cities, and resource-based cities. Moderating effect analysis indicates that rising public environmental attention and internet development strengthen this effect. Spatial econometric analysis further shows that zero-waste city construction generates significant positive spatial spillovers on neighboring regions in addition to improving local ULGUE. This study reveals the underlying logic and micro-level transmission paths of zero-waste city policy, situates China’s experience within global circular economy governance, and offers policy evidence for emerging economies advancing green land use.