اثر رفتار غیر اخلاقی بر اعتماد در یک رابطه خریدار تامین کننده: نقش واسطه تخلف قرارداد روانشناختی

Research on trust in buyer–supplier relationships has tended to focus on the performance outcomes of a trusting relationship, as well as the processes that serve to build trust. Largely absent from the buyer–supplier literature is an in-depth examination of activities that break down trust, and the resulting effect on supplier trust in the buyer. The authors propose and test a model that evaluates psychological contract violations between a buyer and a supplier as a mediating variable of the effect of unethical activities on trust within a partnership. Survey data was collected from 110 tier one suppliers of major corporations in the state of Ohio. Our results show how a supplier's perception of a violation of the psychological contract either partially mediates or fully mediates the relationship between the buyers unethical activity and the suppliers trust in that buyer. We discuss how suppliers may demonstrate bounded ethicality when they overlook perceived unethical behaviors by the buyer.

Toyota surpassed General Motors (GM) as the worldwide leader in automotive sales in the first quarter of 2007. The struggles of American automobile manufacturers to stay ahead of their Japanese counterparts is partially attributable to numerous flaws in the former's manufacturing and management principles, including shortcomings in supply chain management efforts. The philosophies of these companies vary substantially, particularly with regard to supply chain relationships. Japanese automobile companies manage suppliers as extensions of their own firm, working closely with them to reduce unit costs by developing their skills. Meanwhile, American automobile companies are notorious for unilaterally demanding cost reductions from the supplier, utilizing adversarial and potentially unethical techniques which consequentially optimize on short-term performance. For example, GM writes contracts that allow it to shift to a less expensive supplier at a moment's notice (Liker and Choi, 2004). The result of this myopic stance is predictable, often devolving into spiraling distrust between buyer and supplier. Grave challenges face managers regarding their ability to manage relationships and coordinate activities across multiple independent players, as legal documentation is unable to anticipate the many cooperative activities and intense flexibility required for meaningful integration. One manifestation of these new buyer–supplier relationships is the emphasis on trust in lieu of formal contracts. A recent study (Johnston et al., 2004) indicates that higher levels of inter-organizational cooperative behaviors, such as shared planning and flexibility, were strongly linked to the supplier's trust in the buyer firm. Alternatively, unethical business practices can possibly undercut the development of trusting, long-term business relationships. Unethical behavior can lead to negative publicity, substantial fines, and ultimately decreased sales and profits (McGuire et al., 1988). DuPont agreed to pay nearly $11 million to a group of commercial growers because they allegedly withheld critical scientific test data and other evidence regarding the company's Benlate DF fungicide that farmers claimed damaged their crops (Geyelin, 1999). When supplier's trust in a buyer erodes due to the partners unethical behaviors, the supplier has the option to seek alternative business opportunities. The supplier may also communicate negative information with other potential suppliers of the buying firm, possibly causing the buyer to lose some influence over its suppliers. Dunfee (1991) acknowledges that punishment extolled through negative word of mouth need not be administered through a party holding power in the relationship; the power is derived from the community. Building strategic relationships that transcend organizational boundaries has proven a formidable struggle for many managers. This is evidenced in a 2004 Computer Sciences Corporation survey of supply chain progress in which respondent firms note the most underdeveloped area of their supply chain involves developing long-term relationships with suppliers and customers, and consequently this area was in need of the most work going forward. This reveals that beyond basic logistic and infrastructural problems requisite of a firm's time and attention, such as transportation, warehousing, and inventory management, lie equally pressing issues of a “softer” nature, including ethics, trust, and the psychological contract. These represent key aspects of relationship management, and form the basis of the current study. Research that examines the cognitive and psychological aspects of managing the buyer–supplier relationship is sparse. Also largely absent from the buyer–supplier literature is an in-depth examination of activities that break down trust. This paper adds to this emerging research stream by evaluating psychological contract violations between a supplier and buyer as a mediating variable of the effect of unethical activities on trust within a partnership. We define trust here as a firm's reliance upon other entities with which it is engaged to voluntarily recognize and protect its rights and interests (Hosmer, 1995). As such, the governing mechanism of much relationship behavior is an implied obligation of reciprocity (Rousseau, 1989). This suggests a psychological contract exists between the supplier and buyer, defined as a participant's subjective, idiosyncratic perceptions regarding obligations due (Morrison and Robinson, 1997 and Ho, 2005). A perceived violation of the psychological contract may occur through subtle or blatant unethical acts that fail to protect the rights and interests of others. From the supplier's perspective, unethical behaviors by the buyer occur as exogenous variables outside the realm of control of the supplier, and may lead the supplier to experience decreased levels of trust in that buyer. Our research investigates this phenomenon, and seeks to determine the role of psychological contract violation within the ethics–trust relationship. This paper proceeds as follows. First, in Section 2 we survey the academic literature surrounding each of the constructs depicted in our conceptual model, accompanied by the hypotheses to be explored in this paper. In Section 3, we outline our research design. In Section 4, we present our data analysis and in Section 5 discuss our results. Concluding insights for practicing managers, contributions to theory, and directions for future research are provided in Section 6.

The results obtained from our analysis suggest interesting and important implications for buyer–supplier relationship management. First, we empirically demonstrate the significance of psychological contract violation as a mediating variable to the relationship between unethical behaviors and trust. The findings presented in this paper have significant practical managerial implications. Participants in a buyer–supplier relationship must be cognizant not only of the actions of the firm's representatives, but also of the perceptions maintained by the partner firm. Our research shows that these perceptions are an important driver of feelings of psychological contract violation and trust levels. Second, we also show there is a direct relationship between perceived unethical behaviors and trust. It is important for buyers to understand that trust levels may be declining independent of the supplier's experience of psychological contract violation. A buyer firm cannot rely solely on supplier's indications of frustration and disillusionment as an indicator of how trusting the supplier perceives the buyer to be. These findings may be generalized to all buyer and supplier firms interested in developing or maintaining a mutually rewarding relationship with another firm. Third, we extend previous work on psychological contract theory to the field of supply chain relationships, thereby making a theoretical contribution to the field that incorporates a behavioral perspective. Previous research by social psychologists has demonstrated how emotions can affect the wisdom of decisions (Forgas, 1998 and Allred et al., 1997). Recently, research in operations management has emerged that added social psychological variables to research structures consistent with a behavioral decision research perspective (Johnston et al., 2004, Griffith et al., 2006 and Cousins et al., 2006). We have added to this emerging research by showing how the judgment of suppliers is influenced by social psychological variables and how these variables can influence the supplier's level of trust in the buyer. Finally, we examine all of this within the context of the supplier's perspective, which has been largely neglected in the operations management literature to date (van der Vaart and van Donk, 2008). Specifically, our results give the buyer useful hints about the likely behavior of suppliers and suggest ways in which the buyer's own decisions may be perceived by the suppliers. We show that under certain conditions psychological contract violations partially mediate the effect of unethical behavior on trust. However, we show that psychological contract violations fully mediate the relationship between deceit and benevolence in long-term relationships. The study presented here is not without its limitations. First, the cross-sectional design prevents us from making assertions about causation, although we do strongly support with extant literature the process we have outlined. The collection of longitudinal data would allow for a more statistically rigorous evaluation of causality, as well as improved understanding of the development of supplier psychological contracts over time. Second, while our research did fill a gap in the literature by examining the perspective of the supplier, it would be interesting from multiple aspects to extend this investigation to buyer–supplier dyads. In particular, how does the buyer assess the ethicality of his behavior, and furthermore, how ethical does he perceive the supplier to be? To what extent is the buyer aware of violations of the psychological contract, and are there opportunities to repair the harm caused by a violation prior to a corresponding decrease in trust? Moreover, our examination was limited to ongoing relationships of a minimum duration of 5 years. Inclusion of even younger partnerships may reveal differences in relationship dynamics beyond what was uncovered in our study. Finally, further research should attempt to identify additional factors contributing to the relationships described here. It is clear from our results that other factors contribute to feelings of psychological contract violation, and it is managerially important that as many of the factors as possible be brought forth. Structural equation modeling could be utilized to further test this and more complex models. An improved understanding of the role psychological contracts plays in buyer–supplier relationships is long overdue, and holds great promise for enhancing the quality and performance of interfirm business partnerships. We see this paper being broadly compatible with the review of the survey-based research in supply chain integration. We believe that a critical new research direction concerning how buyers and suppliers psychologically define the relationship game will slowly emerge. These non-traditional solutions to supply chain integration can be systemized by the development of a literature based on what is commonly outside of the operations management literature.