公司治理宣告對股價影響

Abstract

政府為因應鄰近區域對於公司治理改革之快速發展，且為形塑我國公司治理之文化與提升我國公司治理機制，並協助一般投資大眾、機構投資者與企業了解公司治理實施成效，因此在103年度完成第一屆（103年度）公司治理評鑑作業說明與指標之訂定，並就此函送各上市公司參考及據以進行自評作業，這是我國首次對全體上市上櫃公司進行公司治理評鑑之作業，此外證交所藉由公司治理評鑑之結果，從中篩選100檔股票來組成臺灣公司治理100指數，希望藉以引導投資者去投資指數成份股之公司，也希望能藉此鼓勵公司管理階層能保持良好公司治理。 本研究採用公司治理評鑑結果與臺灣公司治理100指數成份股進行研究，並以事件日研究法探討相關異常報酬。經實證得知，當公司被納入指數成份股後會產生正向異常報酬且當有利於指數成份股新聞發佈後也會對成份股產生正向異常報酬，此外以ANOVA分析結果顯示假設若都有入選第一屆與第二屆指數成份股之電子業公司其異常報酬會俺住高於在新聞發佈當天較非電子業公司的異常報酬。上述實證結果關鍵因素在於有著良好”公司治理”之公司會有著正的異常報酬，顯示公司治理對於公司之重要性。

The government of Taiwan regulates the first Corporate Governance Evaluation instructions and indicators of the operation. The government then send it to all listed company to instruct them to do self-assessment, which is the first time that the Taiwan government makes all listed company to do so. In addition, the Taiwan Stock Exchange (TWSE) follows Corporate Governance Evaluation and selects 100 stocks to form The ‘TWSE Corporate Governance 100 Index’, hoping to guide the investors how to make investment on the constituent stocks, and also to encourage corporations to work on their corporate governance. This research uses Corporate Governance Evaluation and stock price, which are included in TWSE Corporate Governance 100 Index, to discuss the relevant abnormal return with event study. It is known that the company which included in the index will creates positive abnormal return and it also creates positive abnormal return to constituent stock once the news has released. In addition, the ANOVA analysis shows that the constituent stocks, which are included in first and second TWSE Corporate Governance 100 Index and also in the Electronics industry, has significant higher abnormal return in the news reporting day than that in the non -Electronics industry.The key factor in empirical results of this research is that if a company has good corporate governance will receive positive rewards on its performance in stock market. This further shows that the importance of corporate governance to the corporation.