情事變更原則之研究－以臺越比較法為中心

A Study on the Principle of Change of Circumstances: Focusing on Comparison between Taiwan Law and Vietnam Law

本文初步分析臺灣與越南關於情事變更原則之規範異同。首先，臺越情事變更原則從實務發展到法典化的路徑大致相同，臺灣從早期透過判例揭示情事變更之法理、特別法中承認在特定範圍有適用餘地、在1968年民事訴訟法第397條進行規範，最後於1999年民法第227條之2明文規定，而越南則從保險業務法中出現情事變更原則之曙光、工程法承認國家政策重大變動影響交易條件之情事變更法理、售貨亭事件作為情事變更原則的指標性案例，最後在2015年民法第420條設有明文。其次，在越南協商先行程序之特色立法中，其特殊性在於其為任意性的協商先行、以及協商不影響契約義務之履行。再者，越南法及臺灣法情事變更原則之構成要件大致相同，值得注意者有二：一、越南法之防險措施或得以臺灣民法第217條加以詮釋，惟前者係真正義務，後者為不真正義務。二、臺灣法上顯失公平之判斷，或可以契約繼續履行會造成一方的重大損害之要件作為形式審查的判準，而後實質考量變更程度是否影響當事人的締約決定或交易條件之變更。最後，關於情事變更之法律效果，臺灣以增減給付或變更而越南以調整或終止作為法律效果，二者範圍就文義上有所不同，另外，值得參考者為，越南法上有經濟因素考量之具體規定，然在經濟因素考量之外，或得將非經濟因素同時列為斟酌因素。

This paper makes a study on the principle of change of circumstances, that focusing on comparison between Taiwan Law and Vietnam Law. First of all, Taiwan and Vietnam's principle of change of circumstances from practice to codification is roughly the same. Since the early time, Taiwan had recognized the principle through jurisprudence and special laws, next concretized in Article 397 of the 1968 Civil Procedure Code, and then fixed in Article 227-2 of the 1999 Civil Code. While in Vietnam, the change of circumstances principle was known as transaction changes affected major amendment from national policies in the insurance business law and construction law, as well as the rise of some cases like the typical kiosk case, as the results of Article 420 of the 2015 Civil Code. Secondly, the regulation of re-negotiation in Vietnam is not an arbitrary precedence and the process of negotiation does not affect the performance of contractual obligations. In addition, it is worthy attention in the compositions of change of circumstances principle, Vietnam law's risk prevention measures may be interpreted by Article 217 of the Taiwan Civil Law, but the former is a real obligation and the latter is unreal obligation. Finally, regarding the legal effect of the change of circumstances, in Taiwan it is to increase or decrease payment or change, while Vietnam law is to adjust or terminate contract. In addition, it is worthwhile to refer to Vietnam law has the specific regulation of legal effect based on economic factors, but non-economic factors may be considered as discretionary factors.