Is the metabolic efficiency of smart cities higher? Evidence from China

Comprehending how smart city construction (SCM) affects urban metabolic efficiency (UME) is crucial to comprehensively assessing the policy performance of SCM. This study evaluates how SCM affects UME through a double-difference-in-differences (DID) model according to panel data collected between 2004 and 2021 from 284 Chinese cities. It is found that SCM can promote UME, and this effect increases yearly. Meanwhile, the impact of SCM on UME has spillover effects, spatial decay boundaries and heterogeneity characteristics. Moreover, SCM promotes UME through technological innovation effect (TIE), industrial upgrading effect (IUE), energy saving effect (ESE) and spatial structure effect (SSE). Results from the above contribute to better understanding of the impacts of SCM policies and offer recommendations for emerging nations that wish to improve their UME. The SCM policy ought to be further promoted by the Chinese government.