공동불법행위 손해배상액 산정과 가해자에 대한 피해자 과실 평가

Article 760 (1) of the Korean Civil Code states: “If two or more persons have by their joint unlawful acts caused damages to another, they shall be jointly and severally liable to make compensation for such damages.” In cases of joint tortfeasor liability giving rise to a quasi-joint and several liability (bujinjeong yeondae chaemu), the apportionment of damages attributable to each tortfeasor must be examined through a structured, step-by-step analysis. Specifically, the total amount of the victim’s damages must first be determined. Then, based on the contributory negligence of the victim vis-à-vis the multiple tortfeasors, the reduced amount of damages for which the tortfeasors are collectively liable must be ascertained. This amount, constituting a quasi-joint and several liability, should be further divided into a shared portion and several individual liability of the respective tortfeasors. Subsequently, the internal contribution ratio among the tortfeasors must be calculated in accordance with their respective degrees of fault to determine each tortfeasor’s share of liability. When the degree of contributory negligence on the part of the victim is uniform with respect to all tortfeasors, the reduction can be applied uniformly to ascertain the amount of the quasi-joint and several liability. However, where the victim’s negligence varies among tortfeasors, an additional step is required to assess contributory negligence in relation to each individual tortfeasor. Two principal methods exist for this purpose: the “aggregate evaluation” method, which assesses the victim’s negligence in a unified manner, and the “individualized evaluation” method, which evaluates it separately for each tortfeasor. While the Korean Supreme Court currently adopts the aggregate evaluation approach due to its procedural simplicity and efficiency in calculating the base amount of damages, this approach risks distorting the apportionment of damages by disregarding the varying degrees of contributory negligence applicable to each tortfeasor. Such distortion undermines the fundamental principles of equitable loss distribution and adequate victim redress. In contrast, the individualized evaluation method more accurately reflects the causal relationship between each tortfeasor’s conduct and the victim’s negligence, thereby producing a fairer and more precise calculation of damages. Therefore, in joint tort cases involving contributory negligence, an individualized evaluation of the victim’s fault vis-à-vis each tortfeasor should be adopted. This principle should apply not only in cases where separate actions are brought against each tortfeasor but also in consolidated proceedings involving joint litigation.