Numerous capital market studies have investigated the stock market's reaction to firms switching to and from brand name auditors (Big 8/6/5/4 auditors). However, audit firm brand name is only one possible indication of the quality of an auditor. This study contributes to the existing literature on auditor switching, by examining how the market reacts to auditor switches to or from audit firms that are considered to be industry specialists. Consistent with our hypotheses, we find that firms switching between Big 4 auditors experience significant positive abnormal returns when the successor auditor is an industry specialist, and they experience significant negative abnormal returns when the successor auditor is not a specialist. We also find that these market reactions are more likely to be due to changes in perceived audit quality rather than differential costs of using specialist auditors. In supplemental analysis of switches involving non‐Big 4 auditors, we find that firms that switch from a specialist Big 4 auditor to a non‐Big 4 auditor suffer the largest negative market reaction. Surprisingly, we also observe that the market reacts most positively when a company switches from a non‐Big 4 auditor to a Big 4 auditor who is not a specialist. These results suggest that the market does perceive audit quality differences based on industry specialization to be relevant to the valuation of a company's market value.
