Audit partners’ client portfolios and audit quality. Evidence from partner busyness, industry composition, and rotation
Thesis event information
Date and time of the thesis defence
Topic of the dissertation
Audit partners’ client portfolios and audit quality. Evidence from partner busyness, industry composition, and rotation
Doctoral candidate
Master of Science (Economics and Business Administration) Jenni Jääskö
Faculty and unit
University of Oulu Graduate School, Oulu Business School, Department of Economics, Accounting and Finance
Subject of study
Accounting
Opponent
Professor Lasse Niemi, Aalto University
Custos
Professor Petri Sahlström, University of Oulu
New research highlights the need for transparency in auditors’ client portfolios
Public debate around the workload of auditors, especially those with a high number of clients, has intensified in recent years (e.g., YLE, July 16, 2024). A new doctoral dissertation by Jenni Jääskö (M.Sc. Econ.), completed at the University of Oulu, adds important perspective to the discussion. Her research suggests that while the number of clients does matter, it's the composition of an auditor’s client portfolio that truly drives workload and, ultimately, audit quality.
“It’s a very different job to audit a hundred small, familiar companies than it is to audit a hundred large, new clients,” Jääskö explains. “Simply counting clients doesn’t give the full picture; what really matters is who those clients are.”
The study finds that large and newly acquired clients place the greatest workload on auditors, which can negatively affect the quality of audits. This negative effect on audit quality is especially noticeable in audits of small firms by Big 4 audit companies. By contrast, auditing small and continuing clients tend to demand less time and effort, suggesting that current public concerns should focus more on the structure of portfolios rather than just their size.
However, the insights gained from analyzing client portfolios go beyond workload. Jääskö’s research also finds that industry specialization and diverse client experience can enhance audit quality. Furthermore, regular rotation of engagement partners brings a fresh perspective to the audit without imposing significant additional costs on client firms.
Globally, the trend is already shifting toward more transparency. In the U.S., regulators are advancing a proposal that would require audit firms and responsible partners of public companies to disclose information about their client portfolios and workloads. Jääskö sees this as a welcome development and hopes similar initiatives will follow in Europe.
The key takeaway from the study is clear: to better evaluate audit quality, companies and stakeholders need more insight into the portfolios and professional focus of the auditors behind the reports.
“It’s a very different job to audit a hundred small, familiar companies than it is to audit a hundred large, new clients,” Jääskö explains. “Simply counting clients doesn’t give the full picture; what really matters is who those clients are.”
The study finds that large and newly acquired clients place the greatest workload on auditors, which can negatively affect the quality of audits. This negative effect on audit quality is especially noticeable in audits of small firms by Big 4 audit companies. By contrast, auditing small and continuing clients tend to demand less time and effort, suggesting that current public concerns should focus more on the structure of portfolios rather than just their size.
However, the insights gained from analyzing client portfolios go beyond workload. Jääskö’s research also finds that industry specialization and diverse client experience can enhance audit quality. Furthermore, regular rotation of engagement partners brings a fresh perspective to the audit without imposing significant additional costs on client firms.
Globally, the trend is already shifting toward more transparency. In the U.S., regulators are advancing a proposal that would require audit firms and responsible partners of public companies to disclose information about their client portfolios and workloads. Jääskö sees this as a welcome development and hopes similar initiatives will follow in Europe.
The key takeaway from the study is clear: to better evaluate audit quality, companies and stakeholders need more insight into the portfolios and professional focus of the auditors behind the reports.
Last updated: 2.6.2025