증권관련집단소송에서의 손해액 추정 = Estimating Damages in the Securities Class Action Litigations

다국어 초록 (Multilingual Abstract)

In Korea, securities class actions have been put into effect since the year of 2005. One of the most important issues when a class action lawsuit is taken to court is the estimation of aggregate damages. In this paper, we try to calculate the shareholder damages in class action litigations using the case of Jinsung T.E.C, which was the first target of class action litigations in Korea. In order to estimate aggregate damages, it is necessary to estimate the number of shares damaged as well as the damage per share. This study estimates the number of shares damaged by applying the three existing trading models(proportional trading model, two-trader model and accelerated trading model), and estimates the damage per share by applying the event study method and Ohlson`s model. The estimation results are summarized as follows: (1) The proportional trading model yields the largest number of shares damaged. The estimated number of shares damaged from the two-trader model is 91% of that from the proportional trading model. On the other hand, the accelerated trading model yields the smallest number of shares damaged, which is only 66% of that from the propor- tional trading model or 73% of that from the two-trader model. (2) The damage per share varies more than the number of shares damaged depending the estimation methods. For example, Ohlson`s model yields the estimate of 1,816 Won per share, while the more sophisticated event study method with event date and market factor adjustments yields the estimate of 5,441 Won, the 3 times of the former estimate. (3) The aggregate damages are widely different as much as 4 times depending on the applied estimation methods. This implies that the disputes over the estimation of damages are highly likely to arise between dependents and plaintiffs in class action litigations. The courts may neither adopt the estimation methods nor accept the estimation results proposed in this study as a scientific evidence in an actual class action lawsuit. Nevertheless, estimating damages based on rational estimation methodology is still important since it can serve as a starting point for the out-of-court settlement. Most of class action lawsuits are resolved through settlement prior to court these days due to the effort and expense involved in trial. In this situation, a reasonable estimate of damages may serve not only as a starting point for the settlement but also may serve as an important benchmark that finalizes the amount of damages.