On-Site PhD conferral mrs. Sanne Janssen

Key words: professional skepticism, professional skepticism traits, audit quality, audit input, audit process, and audit output

"The Ins and Outs of Professional Skepticism - Insights into the Effects of Professional Skepticism Traits on the Inputs, Process and Outputs of the Audit"

The objective of an external audit is to provide assurance to the users of financial statements on the quality of the reported information. A quality audit is therefore essential for the functioning of capital markets. The exercise of professional skepticism is often described as a key attribute for a quality audit. However, despite its alleged importance, the concept of professional skepticism is not well understood. This dissertation advances our understanding of professional skepticism by investigating professional skepticism traits as input factors, and drivers of process and output factors of the audit. It shows that professional skepticism traits of auditors are significantly affected by personality traits and other individual differences, and differ significantly across ranks. Further, it suggests that professional skepticism will ultimately affect audit quality as professional skepticism traits are significant drivers of audit process and output factors. The holistic approach used in this dissertation enables providing recommendations for practitioners to enhance the exercise of professional skepticism.