Opportunism has long been highlighted as one of the hazards of complex buyer–supplier relationships. This hazard has become more challenging to manage as the pressure from consumers and the public for improved sustainability-related performance is passed along the supply chain between buyers and suppliers. For example, buyer demands for and supplier implementation of sustainability requirements, such as low carbon emissions or fair worker treatment, are often poorly defined; difficult to document; and subject to change as pressure for immediate improvement builds, as scientific understanding deepens and as societal expectations advance. This complex setting generates tempting openings for either a buyer or supplier to act opportunistically. In an effort to advance both theory and managerial practice, we consider three aspects of sustainability-related opportunism. First, in line with prior research, we focus on defining sustainability-related opportunism as jointly considering the codification of expectations and verification of performance (while allowing for false suspicions). Second, our conceptualization stresses the need to move away from an implied static view to embrace more fully the changing nature of stakeholders’ sustainability-related concerns. For example, supply chain relationships evolve based on repeated interactions as firms influence each other’s beliefs, practices and outcomes. Third, in a related sense, a dynamic model can combine several theoretical perspectives to inform how the balance of transactional and relational governance mechanisms might adapt as our understanding of sustainability changes, institutional forces evolve, and dyadic relationships mature.

长期以来，机会主义一直被强调为复杂的买卖双方关系的危害之一。随着消费者和公众要求改善可持续性相关绩效的压力沿着供应链在买家和供应商之间传递，这种危害变得更具挑战性。例如，采购商对可持续性要求（例如低碳排放或公平的工人待遇）的要求和供应商的实施通常定义不明确；难以记录；随着立即改进的压力的增加、科学理解的加深和社会期望的提高，它会发生变化。这种复杂的环境为买家或供应商提供了机会主义机会。为了推进理论和管理实践，我们考虑了与可持续性相关的机会主义的三个方面。首先，与之前的研究一致，我们专注于将与可持续性相关的机会主义定义为共同考虑预期的编纂和绩效验证（同时允许错误怀疑）。其次，我们的概念化强调需要摆脱隐含的静态观点，以更充分地接受利益相关者与可持续性相关的关注点的不断变化的性质。例如，随着公司影响彼此的信念、实践和结果，供应链关系基于重复的互动而发展。第三，在相关意义上，动态模型可以结合多种理论观点来告知交易和关系治理机制的平衡如何随着我们对可持续性变化的理解而适应，