关键词: 铁矿石供应链金融, Stackelberg博弈, 产量随机, 资金约束, 价格波动

Abstract: As a fundamental industry of the national economy, mining industry is characterized by capital of large amount and for a long period. Supply chain finance is an effective measure to relieve enterprises of capital pressure, because it not only can improve the capital flow of supply chains, but also be widely applied to other sectors such as agricultural, coal, petroleum, and other commodity industries. Since the 21st century, the pricing mechanism of iron ore has shifted from annual agreement pricing to quarterly index one. In recent years, the supply and demand patterns of global mineral resources have also been changing constantly. These phenomena have exacerbated the uncertainty of iron ore prices, making iron ore price fluctuations more frequent. Price fluctuations have always been the main risk factor in commodity trade, certainly including iron ore. The impact of its price fluctuations on upstream and downstream enterprises in the iron ore supply chain should not be underestimated. Through a comprehensive literature review, this study finds that existing studies of iron ore supply chain finance are still rare, especially from the perspective of iron ore price fluctuations. As the world’s largest importer of iron ore, China is highly sensitive to iron ore price fluctuation. In this context, this paper aims to develop a novel advance-payment model by considering iron ore price fluctuation, profoundly analyze the optimal equilibrium decisions of mining enterprises and steel mills, and explore the impact of iron ore price fluctuations on enterprise decision-making and expected revenue. Therefore, this study provides a theoretical foundation for industrial practitioners to make better decisions in an analytical way.
This paper alternatively applies the supply chain finance model, advance-payment mechanism, Stackelberg game and price uncertainty method to the iron ore supply chain. By investigating the properties of yield uncertainty and advance payment, this paper devises a wholesale-price discount coefficient to formulate a two-level Stackelberg game model, in which a steel mill acts as a leader while a capital-constrained mining company represents a follower. This study aims to obtain better equilibrium decisions for both players (i.e., the leader and follower) and evaluate intrinsic characteristics of iron ore price fluctuations. Based on the real-world data, a sensitivity analysis is conducted by considering the mining company’s initial capital and iron ore price fluctuation. This paper uses the MATLAB software to compute the expected revenue and analyze equilibrium decisions in a real-world iron ore supply chain case. The results show that the optimal order quantity of steel mills is about 145 million tons, the optimal planned production quantity of mining enterprises is about 78 million tons, and the overall expected revenue of the iron ore supply chain is about 244 billion yuan. When the iron ore price rises, mining companies intend to increase their planned production quantity and obtain more expected profit. Meanwhile, steel mills keep their optimal order quantity constant to gain more revenue. Another important finding in this case study is that, because of the higher return rate and the more severe capital requirement which mining companies are faced with, steel mills are willing to participate in supply chain finance when the iron ore price is higher. This paper contributes to making a theoretical breakthrough in the area of supply chain finance and provides a real-world application to the iron ore mining industry. For the future research directions, this can be further explored by integrating other key factors (e.g., the results of iron ore production planning and scheduling) influencing the whole iron ore supply chain procedure, to establish a supply-chain-finance risk-warning mechanism for upstream and downstream mining enterprises.

Key words: iron ore supply chain finance, Stackelberg game, random yield, capital-constraint, price fluctuation