사외이사 선임 및 해임 공시가 기업 가치에 미치는 영향

Since the financial crisis in 1997 the reform on the corporate governance structure has become an important issue. The outside director system was introduced in February, 1998. This paper examines the effect of public disclosures regarding outside directors on the firm values, and evaluates the efficiency of the outside director system. The major findings are as follows. First, the appointment of an outside director has a significantly positive CAR, and therefore has a positive impact on firm value. Second, the dismissal of an outside director has no significant effect on firm value. Third, by firm size, big companies have more favorable stock price reactions to the appointment of outside directors than small and medium-sized companies. Also, when outside directors are dismissed, the former have still favorable investor reaction, but the latter have negative reaction. So, we conjecture that investors differentiate the effects of outside directors on firm valuation according to firm size. Fourth, with regard to firm-specific factors, firms with higher debt ratio and higher Tobin's Q ratio, a proxy for corporate growth prospects, have been less positively affected by the outside director appointment. It may imply that they appoint so-called gray directors who have good relations with owners or top management. Rather, the higher largest single controlling shareholder ownership brings more positive stock price reaction, especially for small and medium-sized firms. Last, but not least, as for outside director characteristics, older outside directors whose age is at least 60 have more positive impact on stock prices. It is also the case with outside directors with management experience and expertise