مدیریت زنجیره تامین "سبز" : نقش اعتماد و مدیریت بالا در بازارهای B2B و B2C

“Green” supply chain management (GSCM) has often been associated with highly visible companies (Bowen, 2000) and firms within consumer-focused industries (Buysse & Verbeke, 2003; Hall, 2000; Roht-Arriaza, 1996). As such, GSCM has partly been led by development of consumer awareness of environmental issues (Beamon, 1999; Zhu et al., 2005). This suggest that firms operating in business-to-consumer (B2C) markets have strong incentives to implement GSCM, due to both institutional and stakeholder pressure. However, this leaves the role of GSCM in business-to-business (B2B) sectors relatively unexplored and to-date little is known about: 1) the relative engagement with GSCM among firms in business-to-consumer and business-to-business sectors; 2) the conditions that are necessary for successful implementation of “green” practices in B2B supply chains. This study addresses these issues within the context of 340 buyer–supplier relationships in the United Kingdom, using an innovative research methodology that captures firms' engagement with GSCM practices and minimizes social desirability and common source biases. Our results show that GSCM is relatively limited among firms in B2B markets compared to firms in B2C markets. At the same time, we show that developing trust with supply chain partners, while also having top management support, is a crucial driver of engagement with GSCM among firms in B2B sector but less important among firms in B2C sector. These findings provide considerable insights to managers and marketers of B2B supply chains that seek to respond to a growing interest of environmental performance of supply chain.

The nature of supply chain relationships varies significantly across business-to-business (B2B) and business-to-consumer (B2C) sectors. For example, personal relationships and trust have been suggested to play an important role in B2B settings (Andersen and Kumar, 2006 and Arnott, 2007), and the different characteristics of B2B and B2C supply relationships can have significant implications for the implementation of “green” supply chain management (GSCM) (Cruz, 2008 and Vachon and Klassen, 2007). Firms in B2B markets often have few incentives to engage in GSCM and hence their practices are relatively reactive compared to firms in the B2C sector (González Benito & González Benito, 2006). There is, however, increasing pressure for marketing and supply chain practitioners in B2B settings to improve their environmental practices. Not only to respond to external pressure, but also because it is generally accepted that GSCM can improve firm performance and its competitive position (Sharma, Iyer, Mehrotra, & Krishnan, 2010). “Green” supply chain management has been defined as “integrating environmental thinking into supply-chain management, including product design, material sourcing and selection, manufacturing processes, delivery of the final product to the consumers as well as end-of-life management of the product after its useful life” (Srivastava, 2007, p. 54). Existing research within the field has focused on a number of aspects that often encompass the entire supply chain (see Srivastava, 2007), including total quality management (Klassen and McLaughlin, 1993 and Porter and van der Linde, 1995), lean supply chain management (Kleindorfer et al., 2005, Rothenberg et al., 2001 and Simpson and Power, 2005), reverse logistics (Chan, 2007, Guide and Van Wassenhove, 2002 and Wu and Dunn, 1995), life cycle assessment (Beamon, 1999, Hagelaar et al., 2004 and Stewart et al., 1999), and product stewardship (Michaelis, 1995 and Verghese and Lewis, 2007). Although such approaches have highlighted the dynamics and complexities of implementing GSCM, they tell us little about implementing GSCM within individual buyer–supplier relationships. At the first-tier supply chain level, research has shown that the implementation of GSCM is often driven by regulation (Walker, Di Sisto, & McBain, 2008), customers (Lamming & Hampson, 1996), and requires the support of top management (Lee, 2008) and employees (Drumwright, 1994). Nonetheless, little is known about the comparative engagement with GSCM among firms in B2B and B2C sectors, but it is generally anticipated that firms in B2C sectors are more involved with GSCM because of greater consumer pressure, media scrutiny and their more immediate visibility to stakeholders (Bowen, 2000 and Hall, 2000). In this study we use a novel data collection approach to capture buyer engagement with GSCM activities within the context of 340 buyer–supplier relationships. Our first aim is to understand and compare the extent of GSCM across firms in B2B and B2C sectors. In addition, we seek to examine the conditions under which firms in the B2B sector implement environmental processes into their individual buyer–supplier relationships. We focus in particular on two drivers: The buyer's perceived trust in its supplier, which has been shown to be a significant predictor of supply chain outcomes in B2B settings (del Bosque Rodriguez et al., 2006 and King and Burgess, 2008); and top management support which has consistently been found to be a major driver of GSCM (Drumwright, 1994, Lee, 2008, Walker et al., 2008 and Zhu and Sarkis, 2006). Given the nature of this study, we make three contributions: First, we provide one of the most comprehensive analyses of “green” supply chain management in the U.K. and we explicitly relate and compare GSCM across firms in B2B and B2C sectors. As such, this study extends our understanding of the degree to which GSCM is context dependent. Second, our study furthers existing research in the field of GSCM, which suggests that trust is an important factor for its successful implementation (e.g. Boyd et al., 2007 and Cheng et al., 2008). We therefore contribute to an emerging literature, which suggests that the implementation of GSCM is sensitive to the characteristics of buyer–supplier relationships. Third, we distinguish between industrial, i.e. B2B, and final consumer-oriented, i.e. B2C, supply chains, and compare the extent to which trust, combined with top management support, plays a role in shaping GSCM in both settings. In the following section we briefly review the literature on GSCM and its relationship with both trust and top management support. We then develop a set of testable hypotheses, which encompass trust, top management support and a set of moderating effects. Subsequently, we outline our methodology before presenting a set of results which incorporate descriptive statistics on the relative engagement with GSCM among firms in B2B and B2C sectors, and a set of hierarchical ordinary least square regressions, which explains the role of trust and top management in shaping GSCM. Finally, we discuss the managerial and research implications of our study.

Analyzing the descriptive data for firm GSCM engagement, we find strong support for Hypothesis 1, with significant evidence that the level of engagement with GSCM is greater in B2C markets than in B2B markets. The mean GSCM score of firms in B2B and B2C sectors is 2.23 and 2.52, respectively, and this is significantly different at the 95% level. Further, evidence of the comparatively low performance of GSCM in B2B supply chains is supported by Fig. 2. Fig. 2 illustrates the percentage of firms in the B2B and B2C sectors that lie in each of the four quartiles of the GSCM score. As can be observed, there is a greater proportion of B2B firms in the first and second quartile, indicating that a high proportion of firms in B2B sectors have relatively weak overall engagement with GSCM. 58% of all firms in B2B sectors score below the median for our sample, compared to just less than 50% of the B2C sample. From Fig. 2, it is also clear that firms in B2C sectors have significantly higher levels of engagement with “green” supply chain management, and with respect to the upper quartile of the “green” score B2C comprise 32%, compared to 19% of B2B firms.Having confirmed our expectations about the nature of the “green” supply chain, which strongly suggested that firms in B2B markets are generally less engaged with these practices compared to firms B2C markets, we turn our attention to Table 2, which explore the drivers of engagement with GSCM, paying particular attention to the roles of top management support and trust. The descriptive statistics and correlations for the variables used in these models are provided in Table 1. Taking these into consideration, along with the variance inflation factors produced by our base models 1 and 5 in Table 2, we find no evidence to suggest that mulicollinearity is a concern for our analysis.The results from the hierarchical regressions are presented in Table 2. Models 1 to 5 are concerned with firms in the B2B sector and models 6–10 with firms in the B2C sectors. In the subsequent analysis, comparison is drawn between the B2B and B2C models. The table includes the base models 1 and 6, for B2B and B2C, respectively, with our control variables. Credibility, benevolence and top management support are then added in models 2 and 7. In models 3 and 8, we then consider the interaction effect of top management support and credibility. Similarly, we consider the interaction effect of top management support and benevolence in models 4 and 9, before we add the interaction effect of top management support, credibility and benevolence in the final models (5 and 10). The explanatory power is satisfactory for cross-sectional models of this type and the individual significant levels provide substantial support for our preceding arguments. More specifically, these findings indicate that trust and top management support are important drivers of GSCM, but that the nature of their influence is highly context dependent, and considerably more important in B2B supply chains. Our base models (1 and 6) explain approximately 17% and 14% of the variation in the “green” supply chain management of firms in B2B and B2C markets, respectively. When top management support, credibility and benevolence are included in models 2 and 7, we do not find support for Hypothesis 2a and Hypothesis 2b, which suggested that GSCM will be positively related to trust, but we find strong support for Hypothesis 3, which suggested a positive relationship between top management and GSCM, but only in the B2B sector (p = 0.003). In models 3 and 8, we find support for Hypothesis 4a, which suggests that credibility positively moderates the role of top management support on GSCM, but only in the context of B2B supply chains (model 3). In model 3, we observe a significant increase in the adjusted R-squared from 0.215 to 0.253, and we also observe that this is due to the moderating effect of top management support on credibility, which is strongly associated with improved GSCM engagement in the B2B market (p = 0.005). This suggests that when firms have both top management support at the firm level and trust (credibility) in the supplier they have greater GSCM engagement, compared to firms that only have top management support. Given the results of model 2, it further suggests that credibility is not sufficient for GSCM, but that it needs to be complemented with top management support in B2B markets. However, in model 8, which explores the B2C market, we observe no relationship between top management support or credibility and GSCM in the B2C market, and neither is the change in the R-squared significantly different to model 7. In models 4 and 9, benevolence is substituted for credibility as the moderating influence on top management, and the interaction effect indicates support for Hypothesis 4b, as benevolence also moderates the role of top management support on GSCM, but only in the context of B2B supply chains (model 4) and not in B2C supply chains (model 9). We observe that the moderating effect of benevolence and top management support is a strong predictor of GSCM (p = 0.012). Given the negative coefficient of the standalone benevolence variable in model 4, it suggests that benevolence is contingent upon top management support for GSCM in B2B markets, but not vice versa, as in the case with top management support and credibility. Top management support and credibility thus appear to be stronger complements to the improvement of GSCM. As with model 8, model 9 indicates that neither trust nor top management support, has a significant role in the B2C market. In the final set of models, models 5 and 10, an interaction term between top management support, credibility and benevolence is added, in order to capture a broader measurement of trust. As expected, we find similar results, which suggest that ‘trust’, in a broad sense, does significantly moderate the role of top management support in influencing GSCM, although only in the B2B sector. In terms of our control variables, the results provide substantial support for earlier work, and our base model shows that firm size is a strong predictor of GSCM in both B2B (p = 0.004) and B2C (p = 0.038) supply chains. Similarly, the relative power imbalance between buyer and supplier is also important in both markets, and indicates that buyer is positively associated with GSCM processes. Finally, we observe that supplier sophistication also plays an important role GSCM in both B2B (p = 0.007) and B2C (p = 0.052) supply chains. This effect, however, disappears in models 2 and 6, with the introduction of top management support.