本論文為三個不同主題所構成之文章，其中前兩個主題乃是引入近幾年在網路經濟學裡提出的新概念----雙邊市場，分別用以分析當遊樂園訂定門票時若考量了雙邊市場（指遊客與進駐園區的廠商）因素後，對其門票價格的影響，以及探討當醫療市場處於不同產業結構下，所對應的均衡結果與社會福利又為何。主要結論有：在第一個主題中，獨占的情況下，若遊客端之交叉網路外部性大（小）於廠商端的交叉網路外部性時，遊樂園將提高（降低）其門票價格，且此時有將雙邊市場因素納入考量的園區收益將會提高；但若是存在競爭的情況下，不論哪一方的外部性較大，遊樂園皆會降低其門票價格，導致雖然有廠商面的收入，但在考慮進雙邊市場後的園區收益反而因更競爭而下降。第二個主題則發現，當公立醫院與民營醫院間成本結構沒有差異情況下，社會中同時存在公立醫院與民營醫院，其社會福利可能會高於社會中只存在公立醫院或民營醫院時的情況。
至於最後一主題，我們則是針對為何公營事業需將競爭對手之利潤也考慮進來這點提出疑問，以一混合雙占模型考慮當公營廠商未將競爭對手之利潤完全納入其目標函數時，分析政府的最適民營化政策問題。結論發現：當管制價格為外生時，最適民營化程度視管制價格程度而定，當管制價格低（中，高）時，最適民營化程度為部分民營化（完全民營，完全公營）；而當管制價格為內生時，政府最適民營化政策為完全民營化。

The thesis of the article constituted of three different issues, of which the first two issues introduce a new concept, known as a two-sided market, into the pricing behavior of amusement parks and the welfare of health care market, respectively. Our main findings are as follows: in the first issue, a monopolistic amusement park will increase (decrease) the admission fee if the consumers have a larger (smaller) cross-side network externality and will enable the park to enjoy higher revenues when compared to amusement parks without externality, but in the case of duopolistic amusement parks, no matter which agent has a larger cross-side network externality, amusement parks will always decrease admission fees and receive lower revenues because of the increased competition in a two-sided market when compared to amusement parks without any externality. In the second issue, when the public hospital and private hospital have the same cost structure, the social welfare under mixed duopoly may higher than under state-run and profit-maximizing duopoly.
As for the last issue, we explore the optimal degree of privatization for a public firm which does not need to care about its rival’s profit completely. We find that: when the regulated price is exogenously determined, the optimal degree of privatization depends on the amount of regulated price; that is, if the exogenously regulated price is small (medium, large), then partial privatization (complete privatization, fully nationalization) is the optimal strategy for the government. In the case of the regulated price is endogenously determined, the optimal strategy is full privatization.

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