本文以Twich直播平台作為參考，利用雙邊市場模型討論直播平台對觀眾及直播主的進入費用以及在直播平台上的最適廣告數量。模型中設定觀眾方的效用會因為直播主人數帶來的網路外部性及對廣告的厭惡程度受到影響，且直播主方加入廣告分潤收益。本文不同以往的雙邊市場文章，大部分是把網路外部性外生設定，本文內生直播主方的交叉網路外部性(廣告數量)。主要結論發現，在獨占的情況下，廣告數量的變動不會受到分潤比例的影響，因為雙邊市場的關係，觀眾對廣告的厭惡程度越大，會使直播平台播放更多廣告。在雙邊均為Single-Homing及Bottleneck競爭下的雙占平台中，我們帶入數值分析，發現廣告數量的變動會與分潤比例呈反向變動，Bottleneck競爭下廣告負效用變動會與觀眾的收費呈反向變動。

This thesis takes the streaming platform as an example by using a two-sided market model to discuss the optimal entry fees for the viewers and live streamers, and the optimal quantity of advertisement. In this model, we consider two points different from traditional two-sided market: One is the utility of the viewers would be affected the degree of aversion to advertisement, the other is the live streamers can share platform’s advertisement revenue. This thesis makes a difference from most two-sided market articles by endogenizing the network externality in the streamer’s side through advertisement. The major findings show that under the monopoly circumstance, the optimal quantity of advertisement does not affected by the ratio of sharing advertisement. The more viewers are repelled by the advertisement, the more advertisement is screening on the live-streaming platform. Under single-homing and bottleneck duopoly platform, by numerical analysis, we find out that the effect of revenue sharing ratio on the quantity of advertisement is negative. The optimal entry free of viewers decreases in the degree of advertisement disutility under bottleneck.

1. 前言　　 1
2. 獨占平台　　 6
2.1　 觀眾的行為　　 6
2.2　 直播主的行為　　 7
2.3　 直播平台的決策　　 8
2.3.1　價格的決策　　 9
2.3.2　廣告的決策　　 12
2.4 直播主工商及代言　　 20
3.　 延伸模型　　 22
3.1　 收取訂閱費用GS　　 22
3.2　 不收取費用GN　　 24
4.　 雙邊均為Single-Homing下的雙占平台　　 27
4.1　 觀眾的行為　　 27
4.2　 直播主的行為　　 28
4.3　 兩平台競爭決策　　 30
5. Bottle-neck競爭下的雙占平台　　 34
5.1 觀眾行為　　 34
5.2 直播主行為　　 35
5.3 兩平台競爭決策　　 37
6. 結論　　 41
參考文獻　　 42
附錄　　 44

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