力霸事件對審計客戶股價影響之實證研究

An Empirical Study on the Impact of the Rebar Event on the Audit Clients Stock Price

本研究以監督假說及保險假說的角度，探討力霸事件對會計師事務所客戶股價之影響，事件日包括力霸與嘉食化無預警聲請重整、力霸集團（包括力霸、嘉食化、中華商銀、友聯產險及力華票券）簽證會計師後續分別遭金管會撤銷簽證資格及停業之處分。實證結果顯示，力霸集團簽證會計師客戶及其所屬事務所其他客戶，在重整日皆有顯著負異常報酬，此結果隱含重整日，市場質疑力霸集團簽證會計師客戶之審計價值，此負面認知蔓延至所屬事務所其他客戶。但樣本公司在第一波懲戒日未見顯著負異常報酬，第二波懲戒日，力霸集團簽證會計師客戶再度有顯著負異常報酬。至於在多元迴歸分析方面，實證結果發現樣本公司財務狀況愈差，其負累積異常報酬愈明顯，符合保險假說之預期；但監督假說因代理成本衡量變數不同而有所差異。 Based on monitoring hypothesis and insurance hypothesis, this study examines theimpact of Rebar event on stock price of audit clients surrounding various events,including Rebar unexpectedly files for restructuring and the Financial SupervisoryCommission (FSC) sanctions Rebar auditors and Rebar affiliates (Union Insurance,Chinese Bank and Great Chinese Bills Finance) auditors by revoking their auditqualifications and suspending their audit tasks respectively. Our empirical results findthat Rebar’s auditor clients and Rebar’s audit firm other clients have significantlynegative cumulative abnormal returns(CARs) when Rebar files for restructuring. Thefindings indicate that the market questions the audit value of Rebar’s auditor clients andthat of Rebar’s audit firm other clients as well. We also find that the CARs of our sampleare statistically insignificant during the first time auditor sanction announcement andRebar’s auditor clients experience additional negative CARs during the second timeauditor sanction announcement. Our multiple regression results also show that CARs ofRebar audit firm clients are negatively related to their financial conditions, which isconsistent with the expectations of the insurance hypothesis. The results of themonitoring hypothesis vary on alternative agency cost proxies.