匯豐事件對審計客戶影響之實證研究

Abstract

匯豐證券股份有限公司於民國90年7月2日無預警地向臺灣證券交易所申請停業;經後者調查指出，該+公司財務報表長期未允當表達，會計師卻簽發無保留意見。本研究自審計需求假說之角度，探討此事件對匯豐之簽證會計師事務所的客戶股價以及客戶是否更換會計師事務所之決策的影響。有關客戶股價部份的實證結果指出，該事務所上市櫃客戶之股價於事件期間有顯著的負累積異常報酬，且此事件的影響並不僅限於匯豐之簽證會計師的客戶;該事務所其他會計師之客戶亦受波及，但匯豐簽證會計師之客戶股價的負累積異常報酬幅度大於其他會計師之客戶負累積異常報酬的幅度;而多元迴歸分析的結果亦發現累積異常報酬與客戶的財務狀況顯著相關，符合保險假說之推論。有關更換會計師事務所部份的結果指出，匯豐事件後客戶更換事務所的比率顯著增加，且更換事務所與否與客戶的財務狀況及未來是否現金增資顯著相關，符合保險假說及資訊假說之推論。

To almost everyone’s surprise, Well-Phone Securities Co. filed for suspense of business to the Taiwan Stock Exchange on July 2, 2001. After a thorough investigation, the Taiwan Stock Exchange announced that the company had not fairly presented its financial statements for a long time and yet the audit opinions before this episode were all unqualified. Based on the audit demand hypothesis, this study aims at exploring how this incidence would affect the stock price and the auditor-switching decision of the clients of the CPA firm that audited Well-Phone. Regarding the stock market reaction, the empirical results indicate that the stock prices of the clients showed negative cumulative abnormal returns during the event period. The plunge in stock prices was not limited to the Well-Phone attesting CPAs’ clients; it also occurred to the clients of the other CPAs in the same CPA firm. As might be expected, the magnitude of the former is significantly greater. The multivariate analysis indicates that the cumulative abnormal returns were related to the financial conditions of the audit clients, which is consistent with the prediction of the insurance hypothesis. As to the auditor-switching part, the frequency of auditor switching increased after the event. Empirically, the switch decisions were related to the financial conditions of the clients and their intent during the event period to make a public offering in the near future. This finding is consistent with the inference of the insurance and information hypotheses.