Beware of the “decoupling trap”: identification, evolution, and driving factors of real and pseudo decoupling in China's city-level building sector

Purpose Cities and industries trapped in a “decoupling trap” risk compromising their own, provincial, and even national decoupling progress and dual-carbon targets. As one of the three major emission sources, the building sector’s carbon emissions are of particular significance in this context. Design/methodology/approach Employing conventional decoupling analysis, an auxiliary “decoupling trap” diagnostic lens, and Geo-detector methods, this research examines whether apparent emissions–output decoupling in the building sector is internally supported by changes in energy intensity and carbon intensity, using panel data from 290 Chinese prefecture-level cities from 2005 to 2022. A driver analysis framework further quantifies the individual and interactive factor impacts of factors on genuine versus spurious decoupling states. Findings In China's city-level building sector, the main findings are as follows: (1) After applying the auxiliary trap-related diagnostic lens, over half of the cities show intensity-mismatch or pseudo-decoupling states, while more internally consistent decoupling is mainly found in central, western, and northeastern regions; (2) the geographic center of true decoupling has shifted westward and southward, with over 90% of truly decoupled cities belonging to middle- and high-income groups; and (3) true decoupling is more often associated with joint endogenous structural conditions and external support, with policy-related variables depending on cities' internal foundations. Originality/value These findings demonstrate the value of using a trap-related diagnostic lens as a complement to conventional decoupling analysis, helping distinguish apparent emissions–output decoupling from more internally consistent decarbonization patterns and providing empirical support for differentiated urban mitigation policies.