Institutional drivers and barriers in sustainable procurement: A systematic review and total interpretive structural modelling analysis of local government

Sustainable procurement (SP) is increasingly recognised as a strategic mechanism for advancing circular economy objectives and environmental sustainability. However, limited understanding exists of how the drivers and barriers of SP interact within public-sector procurement systems. This study investigates the determinants shaping SP implementation in local government. Drawing on a systematic review of 74 studies and expert interviews, the research identifies 43 drivers and 16 barriers across 10 thematic categories. Using Total Interpretive Structural Modelling, the study reveals hierarchical interdependencies among critical determinants, showing that government regulation functions as both a foundational driver and barrier. Crucially, knowledge of green procurement mediates how external policy pressures are operationalised via organisational learning and capability development. The analysis highlights a learning asymmetry where external institutional pressures drive SP outcomes when supported by absorptive learning mechanisms, but this pathway eliminates in highly institutionalised settings unless organisations engage in unlearning. Theoretically, the study develops the Institutional–Learning Asymmetry Model, which integrates institutional theory, organisational learning, and absorptive capacity to explain when and why regulatory pressures enable or impede SP implementation. Practically, the findings guide public-sector leaders and suppliers to redesign procurement systems that convert compliance mandates into embedded SP practices supporting the transition towards circular economy.