考慮碳稅之多階層供應鏈存貨管理

Abstract

碳稅政策目前為各國政府對抗暖化並實現綠色經濟的重要政策工具之一，此課稅機制為反映使用能源所造成的二氧化碳排放的外部成本內部化，促使排放源進行減量。 現今產業在產品壽命週期變短以及競爭市場日趨激烈的經營環境下，佔據供應鏈重要的存貨管理除了著重於如何提升客戶滿意度和降低存貨外，減少碳排放量也已經成為一項重要的課題，因此本篇研究將建立碳稅的EOQ存貨管理模式以及建立碳稅的EPQ最適生產量模式，探討多階層供應鏈在考量碳稅機制下如何做出最佳的存貨管理，以達到整體存貨管理成本與碳排放量最小的目標。本篇研究同時亦探討有效稅率，並利用模擬數據作為模式之前提假設，計算出以上三種稅制之平均每期總成本、碳排放量、訂購量、生產量、利潤與單位產品總成本、碳排放量、利潤，並進一步作結果分析。最後透過各個制度特點之探討，進一步比較其經濟效率性、環境有效性等面向，作為政府在規劃溫室氣體減量政策時的參考，設計不同政策工具之最適搭配，以真正落實節能減碳的目標，同時減少產業衝擊。依所處的供應鏈角色，企業可依據各稅制之特性進行財務規劃、採行不同的營運策略，以增進國際競爭力。

Carbon tax is an important tool for governments to combat global warming and achieve green economy. The policy reflects carbon dioxide emissions from the use of energy and internalization of external costs by the taxation mechanism, and prompts the sources of emissions reductions. In current industry, the product life cycle becomes shorter and market becomes more competitive. Except for increasing customer satisfaction and reducing inventory, reducing carbon emission has already become an important issue in multi-echelon supply chain management. As a result, this paper derives three EOQ/EPQ inventory management models, respectively the carbon tax, carbon emissions permissions and progressive taxation. Not only do we explore effective tax rate, but we also set model assumptions to calculate the average total cost, order/production quantity, profit, carbon emissions per period and the average total cost, profit, carbon emissions per product, the above three tax policies, and further do comparative analysis. Therefore, this study also respectively compares the cost, order/production quantity, profit and carbon emissions in the EOQ inventory management model and EPQ inventory management model applied to a carbon tax. Finally, through further analysis of economic efficiency and environmental effectiveness, our study result can be a reference in the planning of the greenhouse gas reduction policy. Based on the characteristics of each tax system for financial planning, enterprises should adopt different business strategies to enhance their international competitiveness.