本研究主要採用Pinopoulos (2017)的垂直整合廠商(VIP)的概念作延伸，探討垂直整合廠商與其他兩家下游廠商在數量競爭下的購併行為。我們的研究結果表明，除了在產品完全同質的情形下，在任何產品差異化程度的範圍內，垂直整合廠商與其中一家下游廠商皆會參與合併，在這種情況下合併後市場的產量皆會提升，進一步帶動消費者剩餘與社會福利的成長；而在產品差異化足夠大，市場競爭力較弱的條件下兩下游廠商的合併才有可能發生，合併後的市場將面臨更低的產量，使得消費者剩餘與社會福利減少。

This paper adopts the concept of Pinopoulos (2017). to analyze horizontal mergers between the vertically integrated producer (VIP), and two downstream producers under Cournot competition. We show that the vertically integrated producer and one of downstream producers will merge when the products are not completely homogeneous. In this case, market output will increase and the consumer surplus and social welfare increase as well; the two downstream producers will merge only if the product differentiation is large enough. In this case, market output will decrease and the consumer surplus and social welfare also decrease.

目錄
論文審定書 i
摘要 ii
Abstract iii
目錄 iv
圖目錄 v
第一章 前言 1
第二章 基本模型設定 5
第三章 廠商均未合併 6
第四章 廠商的購併分析 8
4-1 廠商1與廠商2合併 9
4-2 廠商2與廠商3合併 12
4-3 廠商2的合併選擇 16
第五章 社會福利分析 17
5-1 廠商均未合併時的社會福利 18
5-2 廠商1與廠商2合併時的社會褔利 18
5-3 廠商2與廠商3合併時的社會褔利 19
5-4 廠商合併前後的社會福利比較 19
第六章 結論 22
參考文獻 24
附錄 26
外部廠商 26
廠商1與廠商2合併(只生產其中一種產品) 29
廠商2與廠商3合併(只生產其中一種產品) 31

圖目錄
第四章 廠商的購併分析
圖一:廠商1與廠商2合併前後利潤總合比較 11
圖二:廠商2與廠商3合併前後利潤總和比較 15
圖三:合併參與廠商利潤增加效益的比較 17
第五章 社會福利分析
圖四:廠商合併後消費者剩餘變化程度比較 20
圖五:廠商合併後社會福利變化程度比較 21
附錄
附圖1:廠商合併與未合併情況下，廠商1的中間財價格 26
附圖2:廠商1與廠商2合併時，廠商3利潤總和的比較 27
附圖3:廠商2與廠商3合併時，廠商1利潤總和的比較 28
附圖4:廠商1與廠商2合併前後利潤總和比較(ii) 31
附圖5:廠商2與廠商3合併前後利潤總和比較(ii) 33

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