This study provides novel evidence on the magnitude of switching costs in auditing. Using a discrete choice approach, we infer switching costs from clients’ audit firm choices. The demand estimation reveals that switching costs are significant and vary by direction, with the highest costs associated with switching from non-Big 4 to Big 4 audit firms. Counterfactual analyses of forced switches suggest that switching costs are substantial, ranging from 0.7 billion U.S. dollars (14.2 percent of audit fees) to 1.2 billion U.S. dollars (24.0 percent of audit fees) when aggregated across all clients. Counterfactual analyses of voluntary switching show that the audit market would become highly dynamic and more concentrated if switching costs were removed. Additionally, clients would gain consumer surplus of up to 306 million U.S. dollars (5.4 percent of audit fees) in such a scenario. Overall, our study documents the importance of switching costs for understanding audit market dynamics. Data Availability: Data are available from the public sources cited in the text.

This study investigates the value of auditor industry specialization. In the first step, we use a discrete choice model to derive the first-order demand for auditor industry specialization. Our results reveal that clients have a general preference for auditor industry specialization, relating to both audit firm and audit office specialization. We observe that specializations at the audit firm and audit office level are substitutes. We also find that larger, more complex clients have a stronger demand for industry specialization at the audit office level. In the second step, we use the results from the discrete choice model to quantify the value of auditor industry specialists for clients. We find the overall value of industry specialization aggregated across all clients is 5.2 million USD (0.36 percent of audit fees) and that industry specialization at the firm (office) level is decisive for auditor choice in 4 percent (6 percent) of all cases.