关键词: 乳品供应链, 第三方检测, 网络均衡, 变分不等式

Abstract: In recent years, the dairy industry has suffered a serious crisis of trust due to the frequent occurrence of dairy safety incidents. It is urgent to strengthen the control of dairy product quality. This requires the collaborative management of the upstream and downstream of the dairy supply chain, which can also avoid the opportunistic behavior of different supply chain nodes. As the core enterprise of the dairy supply chain, dairy manufacturers are the key subjects of quality control in the dairy industry. Compared with the independent input of quality and technology resources by all participants, the input of quality and technology resources in the whole industrial chain led by core enterprises is more conducive to optimizing the allocation of resources and balancing the benefit distribution mechanism. For the balance of interests in the supply chain network, dairy manufacturers should increase their investment in the innovation of fresh milk detection technology to play the leading role in the dairy supply chain. When the fresh milk suppliers play a leading role in the quality control effective way to achieve the governance of the dairy supply chain. However, both fresh milk suppliers and dairy products manufacturers are likely to cause opportunistic risks such as“collusion” among upstream and downstream enterprises when considering the maximization of their own interests, which will also have a negative impact on the sustainable development of the dairy supply chain. Therefore, our study consider introducing third-party testing institutions as the main participants in the dairy supply chain to optimize the existing dairy supply chain network structure. By constructing a dairy supply chain network equilibrium model including fresh milk suppliers, third-party testing institutions, dairy manufacturers and demand markets, this paper reveals the impact of changes in the input level of fresh milk testing technology innovation under the invasion of third-party testing institutions on the balanced decision-making at all levels of the dairy supply chain, and explores the government subsidies and punishment strategies under the equilibrium state in combination with the actual business situation of third-party testing institutions, and reconstruct the upstream and downstream benefit distribution mechanism of the dairy supply chain. The results show that: The third-party inspection institutions undertake the investment of fresh milk detection technology, and the greater input of raw milk testing technology innovation, the more improve the testing quality level. At the same time, the risk aversion ability gradually strengthened, the overall profit of the dairy supply chain network increased, which is a beneficial attempt to achieve the management of the dairy supply chain, and has important practical significance for the high-quality operation of the dairy supply chain; Suppliers of raw milk take the leading position in quality control and urge dairy producers to share part of testing cost through price transmission mechanism, so as to alleviate the pressure on them to bear the testing costs unilaterally, and also provide decision-making reference for balancing the distribution of benefits in the dairy supply chain; The government plays a regulatory role in the third-party testing environment, improves the fairness and impartiality of third-party testing institutions through subsidies and punishment measures. At the same time, the government promotes the market-oriented operation of third-party testing by adjusting strategies.

Key words: dairy supply chain, third-party testing, network equilibrium, variational inequality