We examine whether customer-base concentration has a differential impact on profitability for firms contracting with major government customers versus firms contracting with major corporate customers. We document that firm profitability increases with the concentration of major government customers, but decreases with the concentration of major corporate customers. We attribute the contrasting results to the differential impact of major government and corporate customers on demand uncertainty. Specifically, firms contracting with major government customers face lower demand uncertainty that enables them to realize more efficiency gains from customer-specific investments, whereas firms contracting with major corporate customers are exposed to higher demand uncertainty that reduces the efficiency of customer-specific investments. Overall, our study suggests that major government customers are unique and important in the composition of customer base, and they impact firm outcomes in a significantly different way than major corporate customers.

While current audit standards explicitly state engagement partner tenure requirements, firms have flexibility in managing the rotation process. We conduct semi-structured interviews with 20 U.S. audit firm partners who share their experiences on topics including how they identify appropriate candidate partners and what efforts they undertake to manage relationships with clients post-rotation. We investigate firms' motivation to manage the auditor-client relationship through the lens of Social Exchange Theory (SET), and we consider how likely outcomes of this rotation process map onto regulators' intent that a newly rotated partner provides a fresh perspective to the audit. Our study informs regulators and investors about the process by which engagement partners are selected for rotation, documenting that partner assignment is typically not random. Further, our finding that partner rotation is an extended process (rather than a single discrete event) has implications for audit researchers investigating the effects of partner rotation.