Does an Auditor＇s Within-Industry Market Share Still Capture Auditor Industry Expertise in a Mandatory Audit Partner Rotation Regime？

Prior studies commonly use an auditor＇s market share in an industry as a proxy for auditor industry expertise and find that audit quality is positively related to an audit partner＇s within-industry market share in a voluntary audit partner rotation regime where the length of the client-partner relationship is not limited. Mandatory audit partner rotation, however, limits the length of the client-partner relationship and can artificially increase or decrease the market shares of incoming and departing partners, thus making the audit partner＇s within-industry market share an unreliable proxy for auditor industry expertise. Using a sample of banks in Taiwan, we find that audit quality is positively related to an audit partner＇s within-industry market share in the voluntary audit partner rotation regime. However, such a positive relation disappears in the mandatory audit partner rotation regime. Thus, we conclude that mandatory audit partner rotation decouples the link between an audit partner＇s within-industry market share and auditor industry expertise and caution researchers against using an audit partner＇s within-industry market share as a proxy for auditor industry expertise in a mandatory audit partner rotation regime.

Does an Auditor＇s Within-Industry Market Share Still Capture Auditor Industry Expertise in a Mandatory Audit Partner Rotation Regime？

earnings quality, auditor expertise, mandatory partner rotation, client-specific tenure, industry-specificmarket share