更換會計師之市場反應研究:產業專家之影響

Abstract

本研究主要目的在於檢視市場是否能區分不同等級產業專家的審計品質之差異。睽諸文獻得知，公司更換簽證會計師具有資訊內涵。而不同等級的產業專家有不同的審計品質，同時為國家及地方性 (Both national and city level) 的產業專家具有高的審計品質。 本研究再進一步探討此資訊內涵是否因更換會計師審計品質的不同而有不同的影響。本研究將產業專家區分為: (i) 國家級(National level) 、 (ii) 地方級(City level) 、 (iii) 國家及地方級(Both national and city level) 產業專家，以2005年至2008年美國更換會計師之上市、上櫃公司為樣本進行實證研究。主要是測試當公司宣告從非產業專家轉換至產業專家，市場是否會對產業專家不同的審計品質做出不同的反應。 本研究使用事件研究法，探討當公司從非產業專家更換至不同產業專家，是否會呈現顯著正的異常報酬。而當公司從不同產業專家更換至非產業專家，則會呈現顯著負的異常報酬。實證結果並未支持本研究之假說，雖然有些結果於預期的方向一致，但卻不顯著。此議題待日後研究加以澄清。

This paper investigates the market reactions to auditor switches to and from industry specialist auditors. It examines whether the market reaction would be more positive for auditor switching to Both National and City level industry specialist (BS) auditor using the framework developed in Ferguson et al. (2003) and Francis et al. (2005). Prior studies suggest that industry specialist auditors, specifically when the auditor is BS, have higher audit quality compared to non-specialist auditors and that the market reacts positively to firms switching to Big 4 specialist and reacts negatively to firms switching from Big 4 specialist. Thus, if the market is able to distinguish between the differences in audit quality of specialist auditors, I expect that the market would respond most positively to firms switching to BS auditors. This study is based on the Market Adjusted Model methodology used in event studies and consists of examining whether positive cumulative abnormal returns accrue to firms which switch from a non-specialist audit firm to Big 4 specialist audit firm, and vice versa. While some of the results are consistent in direction, the results are not statistically significant. Some implications of this finding are discussed in the concluding section.