Network Games and Optimization with Applications in Supply Chain Operations, Crises, and Policies

Abstract

In the current era of a growing population, systemic changes, and rising risk of crises, humanity is facing an unprecedented challenge of resource scarcity. In a broader sense, the world’s shortage problem since 2019 has ranged from resources such as lumber, metals, and labor, to the end-products such as medical supplies, grocery items, and household cleaning products. In particular, the world's consumption of semiconductor chips, for instance, has surged due to societal changes such as the growing focus on climate-conscious carbon neutrality and remote working styles as a result of the COVID-19 pandemic. However, the supply of rare earth elements, which are critical for producing chips and a range of other essential applications, is under enormous stress. Overall, we are experiencing a shortage economy. Resource scarcity and shortage can be induced by supply, demand, and structural factors. Stressors that contribute to resource scarcity include innate scarcity of the product, competition, demand surge, and supply-side policies. Additionally, certain modern inventory management practices, such as Just-in-Time inventory, can be associated with shortage risks in supply chains at the firm level. As the munificence of scarce resources is akin to the sustainability and growth of individual firms, societies, and the flourishing of humanity, meeting the the demands for scarce resources is a substantive economic, commercial, and societal matter for decision-makers. Historically, supply-side fiscal policies are commonly used by governments as strategic instruments to address resource scarcity. The provision of fiscal policies to a resource sector in scarcity, directly or indirectly, can have an extreme relief and stimulus effect on the management of the targeted sector and the broader economy. Thus, it bears merit to seek an improved socio-economic response to the supply-demand dynamics by integrating policies and environmental risks along with conservation and competition from a supply chain perspective. This dissertation encompasses multidisciplinary research on the economics of supply chains under the context of resource scarcity. It contributes to the equilibrium and dynamics in the modeling and analysis of scarce resource supply chain networks under the scenarios of competition, ownership, interplay, risks, policies, welfare, business practice, and supply chain design. The dissertation begins by outlining the critical issues that are the cause and effect of resource scarcity in Chapter 1. Then a review of the state-of-the-art studies that serve as the conceptual and theoretical foundation of this work is conducted in the same chapter. The technical part of this dissertation, Chapter 2, includes a review of economics concept and operations research methods, upon which, Chapters 3, 4, and 5 are established. Chapter 3 presents a two-period inventory model in a simple competitive supply chain setting. I strive to uncover the interplay between the firms, with a focus on inventory management at an operational level. In Chapter 4, I develop a general decentralized cross-sector supply chain network model that captures the unique features of scarce resources under a unifying fiscal policy scheme. In Chapter 5, I extend the model by incorporating a closed-loop structure and some uncertainty elements. As such, I develop a robust closed-loop supply chain network equilibrium model that investigates a critical material and the semiconductor chip's supply, production, recycling activities, and the uncertainties that arise from the policy shifts. Finally, in Chapter 6, I point out the linkages between Chapters 3, 4, and 5, summarize the major contributions of the dissertation, identify the current research trends, and envision the post hoc research opportunities. The conceptual framework and methodologies discussed in this dissertation can also be applied to a host of extended supply chain design problems and many other areas.