廠商的訂價行為一直是產業組織文獻上一個重要的研究課題。獨占訂價尤其受到經濟學 家與政策制定者的關注。近年來，要素市場差別取價的福利效果無論在理論或實證的文 獻中皆引起廣泛的討論。雖然實務上廠商所生產的產品往往具有異質性，但在差別取價 的文獻中卻鮮少以產品異質性的模型架構來分析要素市場差別取價的效果與政策意 涵。故本研究擬建構一垂直相關市場的模型，且考慮產品異質性及下游廠商的 R&D 投 資決策，來分析要素市場差別取價在短期與長期時對於社會福利的影響及相關的政策意 涵。我們希望藉由此計劃之完成，能對要素市場差別取價的各種效果有更深入的瞭解， 並且建構更貼近於實際現象的理論模型，以針對不同的情況來提出適當的政策建議。本 計畫的主要目標如下: (1) 以產品異質性的模型為分析架構，且分別考慮 R&D 投資為外 生給定與內生決定的情形，來分析要素市場獨占廠商在單一訂價及差別取價下的價格決 策，並藉由比較此兩種訂價決策之下的市場產量、消費者剩餘、廠商利潤及社會福利來 探討要素市場差別取價的福利效果與政策意涵。(2) 延伸基礎模型，考慮不同市場競爭 型態(Cournot vs. Bertrand 競爭)及非線性訂價契約(兩階段訂價)對基礎模型均衡之影 響，以提供更具一般性的理論分析與政策建議。(3)在 R&D 投資內生決定的情況下，討 論要素市場差別取價對於下游廠商進行 R&D 投資誘因的影響及其背後所隱含的政策意涵。 The pricing behavior of firm has long been an important subject in the industrial organization literature. Monopoly pricing in particular has drawn considerable attentions from economists and policy authorities. Recently, there have been extensive debates on the welfare effects of input price discrimination in both the theoretical and the empirical literature. Although empirical observations reveal that firms always produce differentiated products, effects of product differentiation have been overlooked in the literature on input price discrimination. Hence, this project aims to establish a vertically related market model with product differentiation and R&D investment to examine the welfare effects and policy implications of input price discrimination in the short run and in the long run. After the project is accomplished, we expect to get more insights on the effects of input price discrimination, to enable the theoretical model to fit real-world phenomena and to offer appropriate policy suggestions. The main objectives of this project are as follows: (1) Establish a product differentiation model, in which the R&D investment can be either exogenously given or endogenously determined, to investigate the price decisions of an input monopolist under discriminatory and uniform pricing, and then to compare the market outputs, consumer surplus, profits and social welfare under the two pricing policies so as to examine the policy implications of input price discrimination. (2) Extend the basic model by considering different competition modes in the downstream market (Cournot vs. Bertrand competition) and nonlinear price contracts of the monopolist (Two-part tariff) to examine the robustness of the results from the basic model and to provide more general policy suggestions. (3) Endogenize the R&D investments of the downstream firms to explore the effect of input price discrimination on R&D investment incentives and the relevant policy implications behind.
