本研究探討市場上有兩家廠商，且廠商之間的網路規模不對稱。在市場給定相容程度下，廠商做價格競爭，求廠商的最適市占率、最適定價及其利潤。本研究用Palma和Leruth的方法衡量網路外部性大小，消費者必須選擇兩產品其中之一消費。進而探討當產品之間的相容程度被要求提高時，對廠商的市占率、定價及利潤會有甚麼樣的影響。
   本研究與前面文獻不同的有幾點：第一，廠商之間產品的相容性為部份相容，即為廠商之間的系統操作只有部份能在彼此的產品上使用；第二，廠商是進行價格競爭行為；第三，產品之間有垂直差異，意為產品之間的品質有明顯差異；第四，消費者偏好皆為不同，即為消費者對於產品有不同的喜歡程度。基於以上條件，探討廠商間的競爭行為下最適的市占率、最適定價及利潤。並進而討論相容程度提高時，廠商的意願為何。
  最後我們發現當廠商之間的產品相容程度被要求提高時，會造成網路規模較大的廠商其市占率減少、價格降低及利潤減少；相較於網路規模較大的廠商，規模較小的廠商反而市占率會因此增加、價格提高進而利潤增加，由此可判斷出，網路規模較大的廠商會不願意提高相容程度，規模較小的廠商則會想盡辦法提高相容程度。會導致此結果的原因，我們整理出兩個：第一，競爭效果會使廠商之間的競爭行為變得更激烈；第二，網路效果會使使用網路規模較小的廠商消費者增加，進而使另一個廠商的市占率下降，導致規模較大的廠商市占率下跌，消費者的網路外部性下降，讓其的原本的優勢變小了，無法吸引消費者，只好降低價格。

In this paper, there are duopoly firms on the market. The network sizes of two firms are asymmetric. Under the Compatibility that the market gave, two firms do price competition, firms achieve the optimal market share, the optimal price and profits. We use the method of Palma and Leruth (1996) to measure the size of network externalities. Consumers must choose one of two consumer products. And discuss if the compatibility between two products required to enhance. What will affect the market share , price and profit of firms?
There are some different points that this study compared with previous literature：First, the compatibility between the product manufacturer is partial compatibility ; second, two firms are price competition.; third, the vertical difference between the products, meaning products are significant differences between the quality; fourth, consumer preferences are all different, that is, consumers like the product has a different degree. Based on the above conditions , we tried to achieve the optimal market share, optimal price and profit of two firms. And what will the firms do if the compatibility between them is required to enhance. 
In conclusion, we found when the compatibility of products between manufacturers are required to increase,  it will cause the larger network firms to reduce their market share, lower prices and reduced profits. Compared to the larger network firm, the market share of smaller companies will increase, higher prices and thus increase profits. Because of this conclusion, we can determine that the larger the network will be unwilling to increase compatibility of manufacturers; smaller companies will find ways to improve compatibility level. Reasons for this result, we sorted out the two: first, the competitive effects :this make the price competition between manufacturers will become more intense; second, the network effect : it lead the smaller firms to increase its number of customers, then makes the other manufacturer’s market share decline. And then the consumer surplus will decrease, the original advantage fall away. The larger network company has to cut price to attract the customers.

第一章 緒論	7
第一節 研究動機與目的	7
第二節 研究架構	2
第二章 文獻探討	5
第一節 網路外部性	5
第二節 相容性文獻探討	11
第三章 模型	16
第一節 模型建立	16
第二節 靜態分析	22
第三節 相容性的影響	26
第四章 結論	33
參考文獻	35
附錄	40
附錄A	40
附錄B	41

圖表目錄
圖1-1：研究流程	4
圖3-1：消費者偏好分佈圖	19

中文
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