垂直相關產業的出口政策與差別訂價之經濟分析

Abstract

本論文探討在垂直相關的市場結構下，垂直整合對於出口政策的效果與要素市場的差別訂價對於社會福利的影響。 在第二章中，我們利用一個連續寡占模型為主要分析架構，並假設最終財市場位於國外以重新檢視垂直整合在出口導向產業的政策意涵。在過去產業組織的文獻中發現，如果市場產量因垂直整合而增加，則社會福利也將隨之提高。不同於過去的結論，我們發現本國的出口若因垂直整合而增加，則本國的社會福利將因此而減少。此結果說明了垂直整合對於出口導向產業與純內銷產業，在政策意涵上有很大的不同。除此之外，我們亦進一步檢驗，當本國廠商面對國外廠商的競爭與本國廠商同時服務國內消費者時，垂直整合的政策意涵。在此延伸的模型中，我們發現透過垂直整合政策來減少本國廠商的產量，不一定有利於本國的社會福利。 在第三章中，我們分析一要素獨占者的價格決策。此獨占廠商將其中間財出售予一個由許多家在地廠商 (local firms)與一家連鎖廠商 (chain store)組成的下游產業。這些在地廠商與此連鎖廠商各自在其所在的下游市場進行數量競爭。此獨占廠商可採用以下兩種價格策略: 單一訂價(uniform pricing)和差別訂價(discriminatory pricing)。本章將比較在此兩種價格策略下的要素價格與社會福利水準。在基本模型中，我們首先假設此連鎖廠商已向後整合，並具有自行生產中間財的能力。我們發現此獨占廠商可能會對較有效率的在地廠商訂高價。同時，差別訂價並不會改變市場的總產量。然而，若差別訂價可以使市場產量的分配趨於平均，則社會福利仍可因而提高。此與過去研究認為差別訂價只有在提高市場產量的情況下才能夠增加社會福利的結論有所不同。另外，即使差別訂價提高整體的生產成本，我們發現此結論依然成立。在一延伸模型中，我們假設此連鎖廠商必須向此上游獨占廠商購買中間財。同樣地，我們亦發現差別訂價仍可提升社會福利。 第四章中，我們將空間的概念引入垂直相關市場的理論模型以分析差別訂價的福利效果。在空間差別訂價的文獻中，市場範圍與產量在差別訂價之下較單一訂價之下來得大，且社會福利在差別訂價之下也較單一訂價之下來得高。在考慮垂直相關的市場架構下，本論文延伸Holahan (1975) 的模型以重新檢驗中間財市場的差別訂價對於福利的影響。我們發現市場範圍與產量在差別訂價之下較單一訂價之來得大，但前者之下的社會福利水準卻較低。除此之外，即使考慮一般性的成本函數, 此結論仍然成立。 第五章總結本論文，並提出未來可延伸的研究方向。

This dissertation analyzes the effects of vertical integration on export policies and the welfare effects of input price discrimination within a framework of vertically-related industries. In Chapter 2 of the dissertation, we employ a successive oligopoly model that is widely used in the field of industrial organization to serve as the analytical framework, and assume that the output of a final good is for export. We re-examine the welfare implications of vertical integration in export-oriented industries. It is well known that if the total output of the final good increases after vertical integration, the social welfare will also increase. In this dissertation, it is found that, as the number of vertically-integrated firms increases, domestic exports may decrease, but the domestic welfare level can thus increase. Hence, the policy implication of vertical integration in relation to an export-oriented industry is very different from that for a non-export-oriented industry. In addition, we also examine the effects of vertical integration if there are foreign firms competing with the domestic firms in the foreign market or the domestic firms are also serving the domestic market. It is shown that the vertical integration, while reducing domestic exports, may not be advantageous to the domestic welfare. In Chapter 3, we analyze the price decision of an upstream monopolist who produces and sells an intermediate good to a downstream industry where a chain store competes with many local firms. The input monopolist can choose either third-degree discriminatory pricing or uniform pricing. We compare the input prices and the levels of social welfare between the two pricing schemes. In a benchmark case, where the chain store is integrated backward, we find that, if the input monopolist adopts discriminatory pricing, it may charge more efficient local firms a lower input price. Moreover, price discrimination in the input market does not change the total output of the final good and increases production costs, but it can enhance social welfare due to a higher consumption benefit. The same conclusion can also be found in the case where the chain store is not integrated and also serves as a buyer in the input market. This finding is different from the well-known conclusion that price discrimination in final good markets is welfare-improving only if it can raise total output. In addition, this is also different from the conclusion that input price discrimination is adverse to social welfare due to its lower production efficiency. In Chapter 4, we introduce a linear market with vertical relationship to analyze the welfare effect of input price discrimination. In the literature on price discrimination with an endogenous market boundary, it has been shown that social welfare is higher under discriminatory pricing than under uniform pricing as the market area of the former is larger than that of the latter (Holahan (1975)). This dissertation applies Holahan’s framework with a vertically-related industry to examine the welfare effect of price discrimination in an upstream market. We find that although the market area is larger and output is higher, social welfare is nonetheless necessarily lower under discriminatory pricing than under uniform pricing. Furthermore, we also show that this conclusion is valid for a general cost function of the downstream firms. In Chapter 5, we conclude the dissertation and discuss the future extensions.