استفاده از نظریه بازی بمنظور انتخاب استراتژی توصیفی برای خطر زیست محیطی و کاهش انتشار کربن در زنجیره تامین سبز

This paper provides an approach in the context of green supply chain management, using game theory to analyze the strategies selected by manufacturers to reduce life cycle environmental risk of materials and carbon emissions. Through the application of the ‘tolerability of risk’ concept, a basis for determining the extent of environmental risk and carbon emissions reduction has been established. Currently, scant attention is given to holistic supervision of the supply chain with respect to carbon emissions by governments, and thus the starting hypothesis here is that the default strategy that manufacturers will adopt is only to reduce carbon emissions, and thereby environmental risk, in so far as this is compatible with the aim of increasing revenue. Moreover, we further hypothesize that, once necessary governmental policy has been established in the supply chain management, the strategic choices of the manufacturers would be influenced by government penalties or incentives. A case example is provided to demonstrate the insight that indicates the application of game theory. The limitations of the game model and analysis are discussed, laying a foundation for further work.

Supply chain management (SCM) has been brought into academic research since the early 1980s, covering a range of control and planning applications relating to material selection, production, transportation, distribution etc, as well as the potential collaboration among manufacturers, retailers and customers (Blanchard, 2007, p. 8; Harrison & Hoek, 2008, p. 6; Hines, 2004, p. 70; Oliver & Webber, 1982). With global business developing rapidly, the increasing demand for the consumption of commercial products has greatly accelerated the depletion of resources and contributed environmental pollution. Green supply chain management (GSCM) has emerged as a response to the challenge of how to improve long term economic profits and environmental performance (Sheu, Chou, & Hu, 2005). GSCM can be defined as a series of regulations and interventions in the supply chain achieved by attempting to minimize the environmental impact from the suppliers to the end users (Basu & Wright, 2008, p. 245). It is also claimed to be a “win–win” strategy, through which economic benefits can be increased by reducing environmental impact (Zhu & Cote, 2004; Zhu, Sarkis, & Lai, 2008). In this context, GSCM has a substantial influence on the manufacturers within supply chain network, e.g. increasing both opportunities and challenges in green product development, promoting innovative product design etc (Wang & Gupta, 2011). As a consequence, manufacturers will be encouraged, not only to consider the economic benefits, but also to provide ‘environmentally sound’ products having due regard to the Triple Bottom Line (TBL). With integrating clean technologies into supply chain processes, one of the major environmental concerns is the detoxification of industrial pollutants (Wang, 2009), since many common industrial materials used in manufactured products can be considered harmful or ‘hazardous’ to the environment to a greater or lesser extent. The definition of hazardous materials, as given by De Lisi (2006, p. 7) is “anything which, because of its quantity, concentration, or physical, chemical, or infectious characteristics may cause, or significantly contribute to, an increase in mortality; or cause an increase in serious irreversible, or incapacitating reversible, illness: or pose a substantial present or potential hazard to human health and the environment when improperly treated, stored, transported, or disposed of, or otherwise managed”. Examples are the leaching properties of common polymers in the food supply chain, or formaldehyde, a common substance used in some furnishings, which can be carcinogenic. Therefore, the risk to the environment resulting from the complete supply chain involving ‘hazardous’ materials as defined here, and the attendant health implications, need to be carefully assessed in the context of the product life cycle. Certainly, this is scarcely considered in the literature. It follows that there is a need to consider the risk to society associated with everyday consumer products. In addition to the immediate risk posed by ‘hazardous’ materials in use, it is also important in the socio-political context to discriminate within the supply chain the “carbon footprint1”, which may be an increasingly used indicator of the public's acceptance of the product. Notably, though the environmental risk and the carbon emissions in the final disposal stage of a product are often very high compared to other stages (Lee, 2011; Zhu & Sarkis, 2006). Thus, decarbonization has become a significant challenge to the supply chain management by requiring consideration be paid to life cycle stages beyond the supply chain and consumer. This paper proposes a game theory approach that models the likely behaviour of manufacturers in response to drivers to reduce environmental risk and carbon emissions in the context of the green supply chain. A previous study has indicated how life cycle carbon emissions could be displayed as an aid to customer choice, and therefore as a means to send an environmental signal to manufacturers (Zhao, Deutz, Neighbour, & McGuire, 2012). This paper extends the analysis to consider the perspective of manufacturers. Whilst corporations generally respond to a range of signals, from consumers, government within their supply chain, international treaties, regulations etc (Wang & Gupta, 2011), our study provides an initial insight into how they may respond to game scenarios with and without governmental regulations. Game theory will be described in more detail below, but in short, allows the identification of alternative ‘business’ strategies. However, here the emphasis is on reducing environmental risk and carbon emissions without affecting commercial sustainability, irrespective of any governmental or inter-governmental objectives, e.g. international treaty. Although the green supply chain management concept has laid stress on increasing economic returns by reducing the environmental risk and impacts (Zhu et al., 2008), the extent to which the environmental risk and carbon footprint reduction should be incorporated into the management process has had limited discussion. In summary, the authors here propose an approach based on game theory to help manufacturers select appropriate strategies to reduce the environmental risk of supply chain containing ‘hazardous’ materials and carbon emissions in the context of ‘green’ supply chain management.

Game theory offers a valuable tool in the identification of the dominant strategy for increasing performance along the three dimensions of the Triple Bottom Line (Economic, Society and Environment). This study has provided a novel perspective in applying game theory to the green supply chain for selecting appropriate strategies to limit the potential environmental impact, and by inclusion of the principle of the ‘tolerability of risk’. According to the analysis, different strategies have been initially identified and compared in order to reduce the risk, and thus the carbon emissions, whilst maximizing the economical benefits. Moreover, major factors have been identified by the construction of the game model, such as cost and benefit, governmental punitive and incentive policy etc, to provide insight into the problem situation. Thus, this approach informs government and manufacturers' decision-making ability on the appropriate extent of risk and carbon emissions reduction. It is expected that the game model can be fully quantified and validated for further application by means of more case studies. However, the authors recognize that there are limitations involved in the game model. First, the manufacturers are considered as one entity, regardless of the scale, quantity and quality of productions, economic profits, strategies being selected, etc. Secondly, in order to simplify the game model, the interactions between the upstream and downstream businesses, as well as between the enterprises and customers have been omitted. In addition, the consumer preference for environmental friendly products is assumed to be the main factor achieving demand for better, safer and sustainable products for consumption and thus manufacturing innovation. However, the influence of such factors as living standard, public purchasing behaviour etc, have yet to be considered in this study. Thus, further study will centre on the improvement of the game model, including the differences between the manufacturers, the interactions between the upstream and downstream businesses, manufacturers and customers etc. Furthermore, the priority of reducing environmental risk and carbon emissions in different scenarios of the supply chain network will also be considered.