從不完整契約觀點論契約法預設規定的設計－以違約賠償相關規定為核心

Designing Default Rules of Contract Law from the Perspective of Incomplete Contract Theory- A Focus on the Rules regarding Damages for Breach of Contract

李承陶(Cheng-Tao Li)

指導教授 ： 王文宇

國立臺灣大學/法律學院/法律學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.01774

摘要

由於契約當事人可以輕易地以協議排除預設規定的適用，故我國的相關研究向來多以民法條文的解釋論為標的；至於預設規定於契約法中所扮演的角色與功能，我國的多數見解除指出預設規定是立法者為當事人提供的標準化的契約範本外便無任何評論；不過，隨跨領域整合研究的興起，法律經濟學家以不完整契約觀點重新賦予預設規定不同的意義：既然交易參與者幾乎不可能透過完整契約進行交易，則契約法預設規定的目標便是填補這些契約的漏洞。本文於第二章介紹Ayres與Gertner提出的觀點：他們指出立法者於評估預設規定的各種方案時，除應注意市場參與者對於各種方案的好惡以降低使用者於擬定契約條款方面的支出外，尚須將契約當事人與社會於當事人無法排除預設規定時所需面臨的各種成本納入考量；此外，立法者並得進一步地藉由這些成本引導交易參與者從事特定行為，以最大化社會福利剩餘。
　　第三章嘗試以Ayres與Gertner的理論為基礎，針對「履行利益」、「信賴利益」、「返還利益」、「歸入利益」、「約定違約金」及其他關於違約賠償內容預設規定的方案提出分析。違約賠償內容的預設規定將影響允諾人的「投入預防措施成本」與「違約意願」、被允諾人的「進行額外投資意願」、「自行採取預防違約措施意願」與「因違約將導致的利益損害狀態」以及「利用法院解決紛爭的公共成本」等等因素。本文於綜合考量上述因素之後認為履行利益的損害賠償能除了能賦予被允諾人較大的保障外，也能透過較重的違約責任提高允諾人投入適當預防成本的動機；再者，由於證明困難與違約賠償範圍的限制等等現實因素，履行利益違約賠償應不致於過高而誘發被允諾人進行過度額外投資，故應以履行利益作為違約賠償內容的預設規定方能最大化社會福利剩餘。
　　第四章並以Ayres與Gertner的理論分析履行利益的計算基準以及應否以可預見性限制違約賠償的範圍等兩大議題。關於履行利益的計算基準，目前主要有計算使受損者為處於契約義務被履行的狀態所需付出成本的履行成本法則以及計算受損者因契約義務未履行而受有的價值損失的價值差異法則；本文基於契約機制的風險分配功能而認為履行成本法則較符合當事人於締約時的風險分配且不致於產生超額賠償或是經濟上浪費等情形，故可創造較佳的社會福利，這也是我國實務目前採取的主要見解。至於應否以允諾人於締約時對違約損害的可預見性限制違約賠償範圍議題，本文認為採取肯定見解除較能避免契約當事人為策略性不揭露資訊行為，並可以降低資訊揭露的成本。因此，向來奉行台式相當因果關係為的我國實務見解自有修正必要。

關鍵字

預設規定 ； 違約賠償 ； 履行利益 ； 履行成本法則 ； 價值差異法則 ； 可預見性 ； 相當因果關係

並列摘要

Given the fact that the default rules of contract law can be easily opted-out by the agreement of contracting parties, most of the domestic researches focus on the descriptive analysis of default rules in our civil law. But with regard to the role and the function default rules play in contract law, the majority of domestic scholars merely point out the rules are kind of contractual boilerplates provided by the legislator. As the emergence of interdisciplinary research, the advocates of economic analysis of law redefine the role of the default rules in contract law from the perspective of incomplete contract theory: since it is almost impossible for the parties to structure deals by complete contracts, the goal of default rules is to fill the gaps of the incomplete contract. The theory advocated by Aryes and Gertner introduced in Chapter 2 supports that when designing the default rules, the legislator should consider not only the market participants’ preferences among possible proposals, but various cost of each proposal the participants have to bear when they cannot opt-out the default rules. The legislator can further influence the behaviors of the participants by those various cost to maximize social welfare surplus.
This thesis in Chapter 3 takes the theory advocated by Aryes and Gertner as criterion to analyze the respective contractual equilibrium under Expectation Interest, Reliance Interest, Restitution Interest, Disgorgement Interest, Liquidated Damage and other possible proposals for the default damage for breach of contract. This thesis discovers that the default damage for breach of contract will affect the promisor’s cost of precaution against breach and the willingness to breach, the promisee’s willingness to make over-investment in reliance and take self-precaution against breach, the resulting damages from breach and the public cost of resolving disputes through judicial approach. This thesis, after considering all the above factors, claims that Expectation Interest can not only provides the promisee with more sufficient protection but enhance promisor’s willingness to take enough precaution against breach. In addition, given the difficulties in proving the damage and the limited scope of damage for breach of contract, Expectation Interest tends not to be too high to induce the over-investment for the promisee. Therefore, Expectation Interest should be the default rules of damage for breach of contract so as to maximize social welfare surplus.
In Chapter 4, this thesis further analyzes first, the calculating standard of Expectation Interest and second, whether the scope of damage for breach of contract should be limited by the promissor’s foreseeability with the theory introduced in In Chapter 2. For the first issue, courts frequently measure the damages of the injured party either by the cost for completing the performance or the diminution in market value at the time of breach from less than perfect performance. This thesis argues that the cost for completion should be the default rule to measure the damages of Expectation Interest. This is because it will reflect the parties’ assessment and allocation of risk at the time of contracting and will not cause over-compensation or economic waste, which will create more social welfare surplus. Current domestic judicial opinion is of similar view. As for the second issue, the thesis argues that it would be less attractive for the contracting parties to strategically withhold information and the cost of gathering information would be lower, if the scope of damage were limited to those foreseeable by the party in breach at the time of contracting. The domestic judicial opinion, conventionally dominated by Taiwanese Adequate Causation, should thus be revised.

並列關鍵字

Default rules ； damage for breach of contract ； Expectation Interest ； Cost of Completion ； Diminution in Value ； Foreseeability ； Adequate Causation

參考文獻

最高法院23年上字第3968號民事判例

最高法院51年台上字第19號民事判例

最高法院54年台上字第2433號民事判例

最高法院54年台上字第2526號民事判決

最高法院55年度台上字第1338號民事判決