Sustainable public procurement (SPP) is increasingly regarded by governments, international bodies and scholars as a valuable opportunity to address sustainability challenges. Effective implementation of SPP, however, is a complex issue as public organizations are confronted with multiple goals and competing priorities. This research investigates how public organizations respond to this complexity. We draw on a multiple case study design involving 10 public organizations with a comparable high level of sustainability commitment. The findings illustrate how external contexts related to markets, suppliers, regulations, and citizens exacerbate this complexity in SPP implementation. In response, the results reveal that public organizations vary in the way they implement SPP, especially across two dimensions: whether they are focused more (or less) on internal efficiency and whether they are focused more (or less) on sustainability more broadly. Based on these variations, we classify and describe four types of SPP implementation approaches—Compliant/Passive, Convenience, Sustainability-Centric, and Comprehensive. We also found that organizations where sustainability is more entrenched tend to consider it from a more holistic perspective. Finally, we identify factors and features pertaining to organizational setting and organizational self-efficacy that may affect how SPP is implemented. The research contributes to the literature on SPP and sustainability management by illustrating how the implementation of SPP practices does not represent a homogeneous outcome, but varies depending on the degree to which the organization focuses on (internal) economic efficiency vs. sustainability in response to implementation complexity.
