Assessing the carbon emission reduction impact of circular economy practices in construction supply chain: a ridge regression approach

The construction industry is one of the most carbon-intensive sectors, yet existing research on circular economy practices (CEPs) often focuses on isolated practices, leaving a critical gap in understanding their combined impact on carbon emission reduction (CER). This study addresses this gap by integrating a systematic literature review with ridge regression to quantitatively evaluate the synergistic and marginal effects of multiple CEPs within construction supply chains. Drawing on expert evaluations, the findings reveal that waste management, circular procurement, and circular design are the most influential drivers of CER, forming a source-process-end logic chain. By contrast, digital practices such as material passports show limited or even negative impacts, underscoring the need for institutional embedding and integration. The study advances CE research by moving beyond fragmented analyses to establish an empirical model of combinatorial pathways, offering actionable insights for policymakers and industry stakeholders to prioritise effective decarbonisation strategies.