상속세 및 증여세법에서는 한국거래소에 상장되지 아니한 비상장주식은 해당 법인의 자산과 수익 등을 고려한 ‘보충적 평가방법’에 의하여 평가하도록 규정하고 있다. 그러나 선행연구를 살펴보면 상속세 및 증여세법에 의한 비상장주식의 보충적 평가방법은 실제의 기업가치에 비해 과대 또는 과소평가되는 등 비상장 주식의 시장가치를 제대로 반영하고 있지 못하다는 주장이 계속되고 있다. 선행연구에서는 그 대안으로 Ohlson의 회계변수평가모형(accounting-based model: ABM), 산업평균프리미엄모형, 현금흐름할인모형, 초과이익할인모형, 유사기업비교모형, PBR모형, PER모형 등의 기업가치평가모형 등을 제안하고 있다. 이러한 모형들에 의해 산출된 평가액이 보충적 평가방법에 의한 평가액보다 시장가치에 근접한 방법인 것으로 분석되고 있지만, 이러한 방법들은 실무에 적용하기 어렵고, 많은 제약조건들을 규정하여야 하므로 법제화하기가 쉽지 않다는 문제점이 있다.
현행 세법상 비상장주식의 보충적 평가방법으로 이용되는 순자산가치와 순손익가치를 반영하는 방식은 두 가지 요소를 적절히 반영하기 때문에 기업가치 이론상으로도 타당성이 있다. 따라서 본 연구에는 이러한 현행 평가방법의 틀을 유지하면서 선행연구 등에서 문제점으로 제시된 중요한 요인들을 고려한 비상장주식의 평가방법을 제안하였다. 중요한 요인으로는 순손익가치평가에 적용되는 순손익가치환원율과 순손익가치에 반영된 이익으로 산출한 영업권을 순자산가치에 포함하여야 하는지의 여부 및 순자산가치와 순손익가치의 가중평균 비율이다.
분석결과에 의하면 순손익가치평가에 적용되는 1주당 순손익가치환원율은 15%를 적용하고 순손익가치에 반영된 이익으로 산출한 영업권은 순자산가치에 포함하지 않으며, 1주당 순손익가치와 1주당 순자산가치의 반영비율인 가중치는 3과 2의 비율을 적용하는 것이 시장가치에 가장 근접하는 것으로 나타났다.
본 연구는 비상장주식 평가액의 결정요인들을 개별적으로 분석한 것이 아니라 종합적이며 다각적으로 실증분석함으로써 실제가치에 가장 근접한 요인들의 조합을 찾아내어 비상장주식 평가액의 정확성을 높일 수 있는 보충적 평가방법을 제안하였다는 점에서 의의가 있다.
The article 63(Appraisal of Securities, etc.) of Inheritance and Gift tax act states the regulation of unlisted stocks, which are not listed on the Korea Exchange, to be assessed through the complementary valuation method. The complementary valuation method in the article 54(Valuation of Unlisted Stock) of Presidential Decree states the weighted average(3:2 or 2:3) of net asset value and net profit or loss value, the 10% reduction rate of net profit or loss value, and inclusion of goodwill in valuation of the net asset value. The net asset value is net asset amount divided by total stock issued. Net profit or loss value is the weighted average of the net profit per share for the last three years divided by reduction rate of net profit or loss value. The weighted average of the net profit per share for the last three years is the weighted average 3(t-1 period) : 2(t-2 period) : 1(t-3 period) of net profit per shareHowever, the previous research shows that the complementary valuation method is inadequate to be used for the unlisted stocks; furthermore, the actual appraised value is either overrated or underrated in firm value. Thus, the complementary valuation method is not reflecting the actual market value of the unlisted stocks in the stock exchange.
The alternative suggestions include the different valuation models such as accounting- based model(ABM) by Ohlson(1995), Value-to-Book premium model, discounted cash flow model, discounted abnormal earnings model, comparative valuation model, PBR(price to book value ratio) model, and PER(price-earning ratio) model. These models have provided a better approximate valuation of the market value than the complementary valuation method, yet not easy to practice via using accounting documents, in application. Moreover, due to requiring a lot of constraint conditions, it is not easy to legislate into tax law.
The current tax law uses the method of using both net asset value and net profit or loss value in complementary valuation of unlisted stocks; since the net asset value and net profit or loss value are applied with balance, it gives the validity in the theory of firm value.
Therefore, the purpose of this study is to suggest an alternative method of valuation of unlisted stocks by maintaining the frame of valuation methods and consider the negative key factors that were found in the previous research. The key factors are determining whether to include the followings in the net asset value or not: the weighted average rate of net asset value and net profit or loss value, the reduction rate of net profit or loss value that is applied in the net profit or loss value valuation, and the profit that was generated into goodwill in the net profit or loss value.
We consider (1) 15%, (2) 10%, and (3) costs of equity capital by CAPM(Capital Asset Pricing Model) as the reduction rate of net profit or loss value that is applied in the net profit or loss value. We consider to include or do not include goodwill in valuation of the net asset value. And we consider (1) 3:2(weighted average), (2) 2:3(weighted average), (3) 1:1(simple average), and (4) larger between net asset value and net profit or loss value as the weighted average rate of net asset value and net profit or loss value. So, we consider 24 cases(3 cases of the reduction rate of net profit or loss value × 4 cases of the weighted average rate of net asset value and net profit or loss value × 2 cases of inclusion or exclusion of goodwill in valuation of the net asset value).
We calculate the mean and absolute prediction error of valuation models(24 models) and compare each valuation model. The mean prediction error(signed percentage error) is calculated the difference between valuation by each valuation model and real stock price divided by real stock price. The absolute prediction error(absolute percentage error) is absolute value of the mean prediction error. We use 1,092 firm-year observations from listed firms in Korean Exchange, collected for 2008- 2010 period, and empirically test these predictions. The firm-specific financial data is collected from KISVALUE database. The data on preferred stock issue and issues for administration are collected from Korea Exchange. And we received the holding company data from Fair Trade Commission.
The empirical results are summarized as follows. First, the result of the analysis shows that the most adequate reduction rate of net profit or loss value per share in the valuation of net profit or loss value is 15%. This result suggests that the reduction rate 10% of net profit or loss value per share used in current complementary valuation method overvalues complementary valuation estimate. Second, the result of the analysis proposes that the goodwill that was generated by the reflected net profit or loss value was not included in the net asset value. Finally, the result of the analysis shows that setting the weighted rate to be 3:2 ratio of the net profit or loss value to net asset value resulted to be the closest to the market value.
The significance of this study is in suggesting the need of providing an alternative valuation method to increase the accuracy of the appraised value of the unlisted stocks by analyzing the key factors, not by an individual analysis of each factor, synthetically and multilaterally in finding the closest proximity of combination of causes to the actual value.