PhD defence of Ralf Wieriks on Friday 17 May 2013

On Friday 17 May 2013 Ralf Wieriks will defend his PhD thesis entitled 'The Landscape of Sustainability Assurance: Towards Further Shaping the Assurance Approach'. Supervisors are Professors Hans Gortemaker and Gert van der Pijl. Other members of the Doctoral Committee are professors Martin Hoogendoorn, Willem Verschoor (Erasmus School of Economics) and Philip Wallage (Universiteit van Amsterdam) 

Time and location

The PhD defence will take place in the Senate Hall of Erasmus University Rotterdam and will start at 11.30 hrs.

About the dissertation

To regain public confidence, audit firms in recent years have been introducing new types of assurance services that reach conclusions based on non-historical financial information, systems and processes with a focus on sustainability reporting. In his PhD dissertation entitled The Landscape of Sustainability Assurance: Towards Further Shaping the Assurance Approach, Ralf Wieriks researched the role that accountants play in the process of sustainability reporting, particularly where providing assurances for sustainability reports is concerned.

Furthermore Wieriks examines discrepancies between prevailing opinions on how relevant assurance standards should be interpreted and their interpretation in practice. He interviews various experts to supplement his own findings.

Wieriks’ findings indicate that important matters that characterise sustainability reporting do not receive sufficient attention from managers. The aim of his dissertation is to make recommendations regarding the further development of sustainability reporting standards and guidelines for accountants, and to answer the question of how current assurance standards should be interpreted.

About Ralf Wieriks

Ralf Wieriks (1970) became a registered accountant with the Royal Dutch NIVRA after finalizing the post-graduate auditing program at the University of Amsterdam. He has 19 years of experience in the audit practice and is in his current function Director at PricewaterhouseCoopers where he leads the national office for the Dutch Caribbean. He has been teaching auditing and assurance for 12 years at the bachelor and master program of the University of Curaçao in association with the University of Groningen and the post-graduate auditing program of the Inter-Continental University of the Caribbean in cooperation with Erasmus University Rotterdam.

Abstract of 'The Landscape of Sustainability Assurance: Towards Further Shaping the Assurance Approach'

In today’s world corporate social responsibility is one of the conditions for doing business. Companies are expected to be actively engaged in a dialogue with their stakeholders, while transparently accounting for their social, environmental and governance performances by means of sustainability reporting. Auditors become increasingly involved in providing assurance on sustainability reports. This study shows that the assurance approach still has a long way to go in its theoretical and practical development.

The research focuses on how agency theory, the theory of inspired confidence and transaction cost economics apply to assurance engagements on sustainability reports. It also examines the prevailing opinions on how the existing assurance standards should be interpreted and analyses how they are applied in practice. This in-depth study on the rationale, determinants and objectives of sustainability assurance, enriched by interviews with subject matter experts, and combined with an analysis of applied approaches and procedures on actual assurance engagements, results in a unique insight in this new type of assurance service.

This study illustrates that in the assurance practice the matters that characterise sustainability reporting, such as the complex relationship between management and the company’s stakeholders, the importance of management’s behaviour and integrity towards sustainability reporting, the role of internal management processes, and the potential sources of assurance information, do not get the consideration they deserve. Also, in practice no unambiguous relationship could be observed between the set of assurance procedures performed and the determination and communication of the corresponding assurance level. This study also uncovers indications derived from the theories behind providing assurance that are helpful in further understanding and developing precepts that can serve as directives for the standards and guidance on providing sustainability assurance.

More information

Wieriks’ PhD research project is conducted within the Erasmus School of Economics (ESE), Erasmus University Rotterdam.

For more information about this ceremony, please contact Ronald de Groot, Communication Officer of the Erasmus School of Economics phone +31 10 408 1762 or by e-mail:

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