The sample used to test the hypothesis comprises those firms that are short listed for the 2005 ACCA Sustainability Reporting Award. One criterion in the evaluation scheme of the sustainability awards is third-party assurance. Thus, this sample selection increases the probability to obtain a sample that provides sufficient assured sustainability reports to conduct a meaningful statistical analysis. In total, 200 companies are short-listed for the individual sustainability awards. The final sample is reduced due to the fact that, for a variety of firms, either the data for the independent variables cannot be collected, or no sustainability report can be obtained. Sustainability reports are obtained by scanning both the companies’ websites and the database by Corporateregister, which is the world’s largest database of non-financial reports (Mock et al., 2007), or by requesting the report directly to the firm. This leads to a final sample consisting of 136 firms.