How do different policy instruments influence circular economy implementation in the construction sector?

The circular economy (CE) is a promising solution to the growing construction waste and the environmental problems it brings, and government policy instruments are vital for promoting CE implementation. Existing research has been focused on the effects of one or two specific policy tools, like subsidies or fines, on construction CE implementation, which lacked comprehensive comparison among policy instruments and overlooked the stakeholders' consciousness. There are three policy instruments and each has different characteristics and effects. Therefore, based on the Stimulus–organism–response theory, this study comprehensively explored the impact of the three policy instruments on CE implementation, and the mediating role of contractor intentions was considered. The quantitative questionnaire survey and partial least squares structural equation modelling analysis methods were used to study the relationship between the three policy instruments and CE intention and implementation. Then, the qualitative interview method was adopted to validate the results and provide practical advice. The results provide the government with a policy instrument decision-making framework, which gives a theoretical basis and practical implications for the government and contractor companies in CE implementation and gives insight into releasing construction waste and pollution problems.