This paper explores causes and implications of the auditor changes. We investigate the US setting in which the changes are voluntary and there is mandatory disclosure about the reasons for the change. The findings show that changes with a departing Big-4 are motivated by the auditor’s concerns about the client firm weaknesses in internal control processes and compliance with law. The changes between Non-Big-4 auditors are associated with the issuance of going concern qualified opinions, suggesting possible audit opinion shopping by client firms. The switches from a Non-Big-4 to a Big-4 auditor are associated with issues related to the application of accounting standards. Overall, our findings suggest that changes allow auditors to better organise their audit, and balance the objectives of their assignments and the maintenance of effective client relations. The balance of reasonably effective internal controls systems and of risk-proportioned audit fees is at the core of negotiations between audit and client firms. Also, the search for more effective audit and higher governance and financial markets reputation may motivate the switch from a smaller audit firm to a Big-4. The information regarding auditor changes can shed light upon the financial reporting practices and management behaviour, signalling to investors any potential misrepresentation, to the management potential risk areas and to regulators where they might need to intervene to enforce auditor and management independence.
Keywords: Auditor change, Big-4, internal controls, auditor independence