本文利用互補要素模型分析垂直相關市場中之整併策略，並討論在不同談判力下之各種均衡市場結構。當下游廠商所需生產要素之一為獨賣要素，另一由寡占廠商生產時，下游廠商與上游非獨賣要素廠商將視整併後談判力保存程度大小與獨占要素廠商進行補貼與否而決定是否進行垂直整併，上游獨賣要素廠商則會經由比較整併一家下游廠商和任由其他廠商垂直整併所能獲得之利潤，決定在下游廠商談判力較大的情況下併購下游廠商。而當上游非獨賣要素廠商談判力極小或極大時，上游獨賣要素廠商與下游廠商整併亦較為有利。 / This research investigates merger decisions in a vertically-related market with two complementary intermediate inputs by using the Nash bargaining model. The production of final good involves two complementary inputs, exclusive inputs and commonly available inputs. The downstream firms and the oligopolistic upstream firms would merge if the preservation of bargaining power after merger is large enough or the monopolistic input supplier subsidizes them to do so. The monopolistic input supplier compares the gains of merging a downstream firm and the profit of letting other firms integrate. The monopolistic supplier would merge a downstream firm when the bargaining power of the downstream firms is large. Also, merging with a downstream firm becomes more profitable for the monopolistic supplier if the bargaining power of oligopolistic upstream firms is extremely small or extremely large.

本文透過特定之賽局設計，欲觀察廠商在相互整合之現象與原因。內文中之賽局有以下玩家：上游有一獨佔之中間財供應商，而下游有兩種不同類型共三家之最終財生產廠商，而其中一間下游廠商之技術優於其他兩家，其生產最終財之邊際成本較低。賽局之設計為一動態賽局，上游先決定是否進行垂直整合，下游將會觀察到上游垂直整合之意願，並將水平整合視為對上游釋放之友善信號，接著上游廠商將對水平整合之廠商，進一步進行垂直整合；若下游未因上游之意願而進行水平整合，則上游廠商將隨機選擇一間下游廠商進行垂直整合。 廠商於互動時，我們加入不確定性並加以計算並分析；首先是廠商間整合時存在不確定性，由於下游廠商之技術水準為一不透明資訊，換言之，無論是上游觀察下游，或者下游廠商間，皆不了解對方之技術水準，僅知技術水準佳與較差的下游廠商之比例與數量，因此在廠商整合時將面臨整合綜效與技術衰退之風險性；另外，在模型中，加入一整合失敗之懲罰額，當技術較差之兩間下游廠商相互水平整合時，將面臨整合失敗之風險。 經試算後發現，根據這樣的模型設定，若下游未水平整合，或者水平整合之雙方生產技術相異，將會排擠技術較差之下游廠商進行生產；此外，我們亦發現，若進一步分析均衡結果，我們發現，不同技術類型之下游廠商，水平整合之成功(失敗)率，以及兩間技術較差之下游廠商整合後之懲罰金額，皆將影響下游廠商水平整合之意願，若下游廠商不願意進行水平整合，上游廠商經衡量後，將不對下游釋放垂直整合之意願信號，此時廠商間之結構將維持原狀。 本文欲透過加入不確定性，試圖找出與前人研究之異同處；而透過本文之模型設定，我們發現了與前人相似之結論，亦即存在上下游之廠商結構中，將有可能出現廠商間完全分離(沒有任何水平或垂直整合發生)之現象。 / This thesis tries to find out the interaction between firms, especially when these firms face the decision of merging. We also try to figure out the reason why these firms try to merge than stay separation. Here we design a game with some specific conditions for firms to observe the process they merge and the outcomes. In this dynamic game, we design 2 layers, 3 kinds, total 4 firms to be the players of the game. Upstream firm has to make decision whether to merge the downstream firms. Then downstream firms try to merge horizontally after they receive the signal that they knows that upstream firm’s willingness to vertical merge. Here we have to kinds of downstream firms, the one who has better technology has lower marginal cost, in this thesis we assume the marginal cost to be zero. The game have 3 downstream firms totally, so the other 2 downstream firms have the same technology and have the marginal cost above zero. While the downstream firms merge horizontally, they face the uncertainty of the marginal cost changes and the rise of fixed cost, recognized as the failure of integrations. Then the upstream stick to its promise to vertical merge, it will tend to merge the downstream firm which had horizontal merge previously. The result is far beyond the expectation we had before we run this model. The inferior downstream firms will not join the game, even they won’t produce any when the superior downstream firms is vertically merge by upstream firm, no matter the downstream firms merge each other. More, the probability of success in horizontal merge will affect upstream firm to make the decision of vertical merge. The game has only two equilibriums in the end, one is all firms stay separately, and the other outcome is one inferior downstream firm will rule out from the game, and other firms will be merge to one firm and become the monopoly firm in the entire market.