中間財差別取價的經濟分析

Abstract

本篇論文旨在分析垂直相關市場中，上游獨佔廠商第三級差別取價的福利效果。我們將分別考慮以下三種情況，分別是：下游產業結構改變、技術授權與廠商的生產技術水準。 在第二章中，我們考慮了差別取價有可能使得下游產業結構發生轉變，並重新檢視中間財差別取價的福利效果。我們發現，在差別取價之下，當有新的廠商進入市場，相較於單一訂價，社會福利有可能會提升。但是當新進入廠商生產效率太差時，允許差別取價反而會使得社會福利下降，亦即，當下游市場是獨佔之下的社會福利，反而會比下游市場是雙佔之下要來的高。所以，允許差別取價會提升或損害社會福利不能只由下游市場結構或最終財總產出來判斷，廠商之間相對的生產效率也是一個重要的因素。 在第三章中，我們考慮外部廠商利用固定權利金授權法，授權下游廠商新生產技術的可能性，並檢視差別取價的福利效果。我們發現，上游獨佔廠商能否差別取價將顯著地影響到外部廠商的授權行為。當差別取價不被允許的情形下，外部授權廠商會減少授權廠商家數，以壓低中間財價格，抑制上游獨佔廠商利潤剝削的能力。但在差別取價之下，外部授權廠商無法利用授權廠商家數的變動來影響中間財價格，此一結果使得在差別取價之下，有較多的下游廠商拿到授權，只要整體生產效率提升的好處可以勝過中間財訂價所造成的資源扭曲，社會福利就會提升。但是，如果上游獨佔廠商是外國公司，則允許差別取價一定會使得社會福利下降。 在第四章中，我們採用Cobb-Douglas生產函數來取代文獻上固定生產係數的設定，並重新檢視規模報酬如何地影響差別取價的福利效果。我們發現，當規模報酬遞減的現象夠顯著時，低邊際生產成本的下游廠商產出雖然較高，但因為規模報酬遞減的情形太過顯著，其在中間財的生產效率上較低，上游獨佔廠商反而會對低邊際生產成本的下游廠商訂定較低的中間財價格。此舉提升了下游產業的生產效率，也改善了社會福利。再者，不同於Yoshida(2000)，我們發現，當我們將生產技術的規模報酬也考慮進去後，最終財總產出的增加並不是社會福利惡化的充分條件。 第五章總結本論文並提供往後研究的延伸議題。

This dissertation analyzes the welfare effects of third-degree price discrimination in vertically related markets involving endogenous market structural change, technology licensing and returns-to-scale production technology. In Chapter 2, we re-examine the welfare implications of input price discrimination in vertically-related markets by considering the market structural changes. We find that discriminatory pricing may be superior to uniform pricing in terms of welfare if there are new downstream firms to be served under discriminatory pricing. However, if the new entrants are too inefficient, price discrimination may lower the social welfare. Therefore, the social welfare under a monopoly may be higher than that under a duopoly. The welfare effect of price discrimination not only depends on the downstream market structure or the total output but also on the relative production efficiency. In Chapter 3, we examine the welfare effect of price discrimination in the presence of fixed-fee technology licensing in a vertically related market. It is found that price discrimination by an upstream monopolist may significantly change the licensing behavior of an innovator. If the upstream monopolist is not allowed to price-discriminate the downstream firms, the innovator would have an incentive to license its technology to fewer firms in order to suppress the rent to be extracted by the upstream monopolist. But this incentive is absent when price discrimination is allowed. This incentive plays an important role in the welfare effects of upstream price discrimination. It is found that price discrimination by the upstream monopolist may raise social welfare as long as the efficiency gain from more licenses dominates the efficiency loss from input market distortion. This result is opposite to the general outcome of the literature when technology licensing is absent. Moreover, if the input supplier is a foreign firm, price discrimination necessarily lowers the social welfare. In Chapter 4, we replace the assumption of a fixed-coefficient production technology which is common in the literature by a Cobb-Douglas production technology to investigate how the welfare of input price discrimination is affected by the production technology’s returns to scale. We find that when the production technology is sufficiently decreasing returns to scale, the upstream monopolist may charge the more efficient downstream firm a lower input price owing to the lower marginal returns in inputs. This improves the downstream production efficiency and advances the social welfare. Moreover, contrary to Yoshida (2000), an increase in the total output of the final goods is not a sufficient condition for welfare deterioration if the returns to scale are taken into account. We conclude this dissertation in Chapter 5 and offer some extensions.