為了促進我國資本市場之效率性,我國主管當局自2003年開始辦理「資訊揭露評鑑」,一直到2014年結束,總共進行了12屆。資訊揭露品質對於市場的影響,不管是在國內外的文獻上均為重要議題。本文採用交易策略研究方法來觀察評鑑結果的長期市場反應,這是國內首次將交易策略研究方法運用於資訊揭露評鑑之研究。以往國內針對資訊揭露之相關研究,主要使用「事件研究法」觀察評鑑宣告的短期市場反應,然而實證結果並不一致。 交易策略研究方法在財務會計的運用非常廣泛,本文採用在文獻上最常出現的買入持有(Buy and Hold)交易策略來衡量資訊揭露評鑑的市場效果。Barber and Lyon(1997)認為平均買入持有異常報酬是一個適當的估計式,它能準確衡量出投資人所獲取的績效。本研究交易策略,買進評鑑結果較優之公司(A++ & A+)股票,同時賣出評鑑結果較差之公司(C & C-)股票,並握持一年,直到下屆評鑑結果公布,並依此重新建立投資組合。本研究主要實證結果發現,買入持有相對資訊揭露評鑑優劣之交易策略,在長期並無法擊敗台股大盤。
Improving the capital market efficiency of Taiwan, regulatory body set up the 「Information Disclosure and Transparency Ranking System」at 2003 and evaluated the information disclosure compliance of public firms untill 2014. It is really an important issue of stock market reaction to information disclosure and transparency ranking (IDTR, thereafter). This paper use trading strategy research method to gauge the long-run market impact to IDTR. To our knowledge, this paper firstly applies trading strategy method into corporate information disclosure quality research in Taiwan. Comparing with literatures, they measure the short-term market responses by event study method and find out something mixed. Trading strategy method is popular in finance and accounting fields. This paper adopts buy and hold trading strategy to estimate the market effect for IDTR. Barber and Lyon(1997) documented the average buy and hold abnormal return was a feasible estimator which could precisely appraise investors’ performance. Specifically, we long the superior IDTR companies (A++ & A+), short the inferior IDTR companies (C & C-). The portfolio holds till the next time IDTR result making public and rebalances accordingly. The long term performance of relative IDTR superior-inferior trading strategy could not beat the Taiwan’s market index