Sustainability-related opportunism in buyer–supplier relationships: a behavioral perspective on passive vs active forms and integrity-based trust

Purpose The evolving and fragmented nature of sustainability standards in supply chains (SCs) creates scope for opportunism in buyer–supplier relationships. This study aims to adopt a behavioral view to examine how active and passive forms of sustainability-related supplier opportunism influence buyers’ response following an initial occurrence. It also investigates how these effects evolve after repeated occurrences and how suppliers’ integrity-based trust indirectly shapes these responses. Design/methodology/approach This study uses a multistudy sequential design. The first study uses a best-worst scaling (BWS) survey to evaluate the perceived severity of active and passive forms of supplier opportunism. The second study comprises two vignette-based experiments (Study 2a and b). The first experiment adopts a two-group between-subjects design and compares buyers’ responses to active vs passive forms of supplier opportunism and their tolerance for repeated opportunism. The second experiment was a 2 × 3 between-subjects design varying opportunism form (active vs passive) and opportunism occurrences (one, two or three) to test hypothesized relationships. Findings The results of Study 1 show that active forms of sustainability-related supplier opportunism are perceived as more severe than passive forms. The first vignette experiment in study 2 provides evidence that, in sustainability-related contexts, buyers initially tolerate passive opportunism, but its negative effects increase as occurrences accumulate. The results of the second experiment further show that buyers’ intentions to continue are significantly lower in the active opportunism condition than in the passive opportunism condition. In addition, a significant interaction between opportunism form and occurrences indicates that the effect of opportunism form varies as the number of opportunism instances increases. The findings also show a significant indirect effect of supplier integrity-based trust on the relationship between opportunism form and continuation intentions. Originality/value This study advances the behavioral supply chain management literature by providing an account of sustainability-related opportunism and its relational outcomes, moving beyond the dominant transaction cost economics view that underpins prior work.