稀缺性商品市場之兩階層供應鏈合約設計研究

Abstract

當商品面臨非常稀少、市場需求強烈而缺乏的情況下，買賣雙方也就是上下游廠商，需要不同於以往的合約設計型態來有所因應。天災或是其他因素造成供應鏈中斷時，一些品牌廠商為了鞏固零組件及原料的供應正常，願意支付更高的價格來得到更多的數量。本研究針對此採購價格與交易數量呈現正向關係的現象，以Stackelberg模型為基礎，建構兩階層供應鏈的合約模型。依決策時間點而言，上游為先行者，將採購價格與交易數量的正向關係提供在合約中，下游即跟隨者接收合約後，根據合約的價量關係及市場環境來決定其訂購數量。最後下游再將經過加工組裝後的商品賣入零售市場。在此提出兩個模型: 線性合約模型與階梯合約模型，來描述合約中產品採購價格與交易數量的正向關係。本研究討論此兩模型於單一價格收費與區段價格收費兩種不同的收費模式下，上游與下游的反應，並整理出所有可能的情況。由此可對應出決策者目前問題面臨的情況為何，又該如何做出相對應的決策。最後進行數據分析，探討模型可能存在的趨勢。

An unexpected supply chain disruption or a strong demand in a retail market causes some goods to become scarce. Some branding companies agree to a higher price with more quantity of the goods to secure needed components from the key parts suppliers. The purchase price and the acquired quantity behave a positive relation. This study focuses on this uncommon, but important characteristic case and designs the transaction contracts for the business to business market (B2B). We introduce a Stackelberg-type model consisting of a leader (the upstream firm) and a follower (the downstream firm). The upstream firm determines the form of positive relationship between the unit purchase price and the acquired quantity in the contract to maximize its profits where the downstream firm chooses the acquired quantity of goods after learning the contract variable announced by the upstream firm to maximize its profit function. There are two proposed models, linear contract model and step function contract model, to describe the positive relationship under two different charging schemes, uniform and block pricing scheme. We summarize the possible situations of the behaviors of the downstream firm and obtain the corresponding decisions of the upstream and downstream firms.