Assurance on Sustainability Reports: A Study of Factors Influencing the Selection of an Assurance Framework

Abstract

Credibility is added to companies' sustainability reports by obtaining assurance on them (Simnett, Vanstraelen and Chua 2009). Credibility is further enhanced by obtaining sustainability assurance under an assurance framework. We examine the factors that influence the selection of a sustainability assurance framework for the purpose of assuring sustainability reports. We use four categories for the selection of an assurance framework: no international frameworks, one of two international frameworks (ISAE 3000 issued by the IAASB or AAlO00 issued by AccountAbility), and simultaneous use of both international frameworks. We use both multinomial and multilevel logistic regression models to determine the factors that are associated with the selection of sustainability assurance frameworks. The results of this paper show that the type of assurance provider (whether the assurance provider is an audit firm, or an engineering firm), one client company specific factor (size), one industry specific factor (whether a client company is in the mining industry or the finance industry), and the country in which the client company is headquartered, are significantly related to the choice of a sustainability assurance framework. Our study provides insight into sustainability assurance framework preferences.