從公司治理探討基亞條款對生技醫療相關產業股價之影響

本研究以生技醫療相關產業為觀察標的，並由公司治理的角度出發，運用Chen, Kao, Tsao and Wu（2007）所提出之公司治理指標，除CEO雙元性、董事會規模、管理層持股、大股東持股外，並加入資訊透明度，共五項指標。結合事件研究法檢視2014年10月3日證券監管單位公布施行「上(興)櫃公司重大訊息發布應注意事項參考問答集」（因基亞股價重挫所致，故稱之為基亞條款），對臺灣生技醫療相關產業與股票異常報酬率之影響。探究基亞條款事件發生時，對於投入公司治理的差異程度，是否會造成股價波動的變化。實證結果指出，事件宣告後，在短期績效表現，對中度公司治理股票之股價產生負面影響最大，低度公司治理次之，影響最小者為高度公司治理。在長期績效表現，隨著時間拉長，三者標準化累積平均異常報酬率（SCAR）於區間反覆盤整後，隨之反彈上揚，並出現正向累積報酬，顯示三者已漸漸走出基亞條款事件宣告之陰霾；此波反彈多頭走勢，以低度公司治理最強勢，高度公司治理次之，中度公司治理最弱勢。實證結果發現，基亞條款事件宣告對生技醫療相關產業有著整頓調適期的陣痛短空與浴火重生後的穩健長多之影響；且公司治理和公司股價績效具有相關性，證明公司治理品質會影響公司價值。

關鍵字

公司治理；基亞條款；事件研究法；累積異常報酬

並列摘要

The purpose of this study is to explore the effect of Medigen clause on the stock prices of biotechnology and medicine Industries from the perspective of corporate governance. This research focuses on five corporate governance indicators, including CEO duality, board size, shareholdings of the management, blockholder shareholding and information transparency. The first four indicators are proposed by Chen, Kao, Tsao and Wu ( 2007). By using event study methodology, we examine the effect of Taiwan FSC’s matters needing attention of disclosure of material information of listed company at over-the-counter and at emerging stock market, so-call Medigen Clause, on stock abnormal returns of biotechnology and medicine Industries. This study, in the event that Medigen clause announcement occurs, investigates the relationship between the extent of corporate governance and stock price fluctuation. The empirical evidence shows that after the announcement of Medigen clause, it has the greatest negative impact on the stock price of the companies with middle level of corporate governance, followed by the companies with low level of corporate governance and then the companies with high level of corporate governance. As to the long-term performance, as time goes by, the standardized average cumulative abnormal return rate (SCAR) of stock price of those companies will fluctuate, rebound rapidly and show the positive cumulative return. Evidence indicates that those companies with different level of corporate governance will gradually get rid of the negative effect of Medigen clause announcement. The rebound speed of stock price is high among the companies with low level of corporate governance, followed by the companies with high level of corporate governance and then the companies with middle level of corporate governance. The empirical results suggest that Medigen clause have negative impact on the biotechnology-related industries in the short term and positive and long-lasting effects in the long term. Moreover, corporate governance and company stock price performance are closely related to each other; that is, the level of corporate governance will affect the company value.