The Development of Worldwide Sustainability Reporting Assurance

This research investigates the development of assured sustainability reports (SRs) during this century's first decade. More specifically, it presents basic descriptive data on a sample of 148 SRs published in 2006 and 2007 and contrasts this sample with the sample discussed in Mock et al. 2007. The prior study examined a sample of 130 assured SRs issued between 2002 and 2004. Both samples provide information about the nature of SRs, allowing us to investigate important questions such as which countries and industries are more likely to have an assurance statement, what levels of assurance are provided, and what factors affect the level of assurance provided. In addition to providing descriptive data relative to the above questions, we run logistic regressions where the dependent variable is whether a Big 4 firm provided the assurance for both periods being considered. Some important differences are observed related to whether the assurance provided applies to both the quantitative and qualitative assertions made in the report (significantly negatively associated with the Big 4 in the 2002-2004 period, but not significant in 2006-2007), whether the report uses symbols to identify assured statements (significantly positively associated with the Big 4 in the 2002-2004 period, but not significant in 2006-2007), and whether the procedures used are disclosed (not significant in 2002-2004, but significantly positively associated with the Big 4 in 2006-2007).