民法第一八四條第二項規定，違反保護他人之法律者，推定其有過失。往昔學說對此條文的探討，僅著重在(一)其是否應適用及利益之保護，(二)從法規目的來決定何謂保護他人之法律。本文則從經濟分析及普遍性的案例研究，以過失推定為研究重心，給予其理論基礎，並嘗試說明實務及理論的差距。本文認為，民法中的侵權行為法本質上為一事後損害賠償機制，其目的在於以損害的移轉與否，促成社會整體最大的福利。其初步將損害客體分為權利與利益，加諸行為人及受害人不同程度的舉證責任，有其訴訟經濟的功效。其他法律所規定的行為標準，法院可以援為其認定賠償責任的參考因素，的確有助於減輕其訊息處理負擔，不過，也因此導致濫用。民法第一八四條第二項將違反保護他人之法律，實證化其為過失推定，即有過猶不及之憾。如此一方面，造成法院與法律外部環境的隔絕，另一方面，亦造成了法院以之為規避其應實質認定過失的責任，因此破壞了整體侵權行為法的結構，實非司法之福。

　　　　　Article 184II of the Civil Code provides that a person who violates statues designed for the protection of others shall be presumed to be negligent. Traditional legal discussions on the provision have been restricted to (1) whether it shall it apply mutandis mutates to the protection of interests; and (2) the determination of a provision as "protective" shall be based on its legislative purpose. In contrast, this paper applies an economic perspective and uses comprehensive case studies to perform analysis. The author finds the tort system to be an ex post compensation mechanism. Courts often use ex ante standards set forth in protective statutes to determine a defendant's liability, which while effective in lessening courts' burdens, is vulnerable to misuse. Its practice has caused law to become isolated from the external environment and eroded the coherence of tort law as a system. To avoid such misuse, we propose that the courts should always bear in mind that the structure of tort law is efficiency-based. Courts, taking into account economic reasoning, would be more prudent in their judgments.