This study examines whether common ownership by institutional investors is associated with auditor sharing among their investee companies. Auditor sharing can enhance audit quality through facilitated monitoring and improve financial reporting comparability—two benefits that enable common owners to internalize externalities across their portfolio firms (i.e., to reduce negative spillovers from audit failures and to capture positive spillovers from improved comparability across commonly owned peer investees). Using same‐industry company pairs in the United States, I find that common ownership is positively associated with the likelihood of sharing the same audit firm, and this association is stronger when co‐owners have longer investment horizons or more aligned incentives. A quasi‐experimental test leveraging BlackRock's acquisition of Barclays provides consistent evidence. Additional analyses indicate that shared board members serve as a potential channel through which auditor sharing arises. Finally, commonly owned, auditor‐sharing companies exhibit higher audit quality and are more likely to collectively dismiss auditors following revealed failures, consistent with improved oversight. These findings contribute to the literature on shared auditors, auditor choice, and common ownership by showing how a noncontractual relationship induced by common ownership shapes auditor sharing across companies and influences the shared auditor's incentives.

Public accountants are in high demand by non‐accounting firms. While this demand attracts high‐quality accountants to public accounting, it can negatively impact audit quality by distracting auditors. We find that the number of metropolitan statistical area–level busy season job postings for public accountants by non‐accounting firms is positively associated with misstatements. Results are most pronounced (1) when outside job opportunities are from non–publicly traded companies, which likely provide better work‐life balance, and (2) when auditors are under a heavier workload, as captured by higher audit fee‐to‐auditor ratios and increased job postings by audit offices leading into the busy season. Results also suggest that accounting firms that provide large pay increases before the busy season can mitigate the negative audit‐quality effects of busy season job postings for public accountants. These results suggest that accounting firms are not immune to negative effects of auditor distraction from outside job opportunities despite accounting firms knowing that their auditors are highly sought after by non‐accounting firms.