Sustainability reporting in the aviation industry: worldwide evidence
Authors: Karaman Abdullah S. , Kilic Merve , Uyar Ali 
Published: September 2018

PurposeThe purpose of this study is to investigate empirically what affects Global Reporting Initiative (GRI)-based sustainability reporting and its relationship with firm performance in the aviation industry between 2006 and 2015.Design/methodology/approachThe authors derived data from the GRI Sustainability Disclosure Database and Thomson Reuters EIKON; from the former, they downloaded GRI-based reports, and from the latter, they obtained financial data. The authors performed four-level analysis – report existence, report count, application level of report and firm performance –using various regression models (i.e. logistic regression, Poisson regression, ordered logistic regression and ordinary least squares regression).FindingsFirst, the authors based the analysis on the existence of GRI-based sustainability reports, which showed that firm size and leverage are positively associated with sustainability reporting. Contrary to expectations, ownership was negatively associated. Furthermore, free cash flow per share, growth and profitability do not have significant effects on sustainability reporting, in contrast to expectations. Subsequent analysis was based on report count (number of total published reports within the examination period) and application levels of reports. Compared to the preceding analysis, there were no notable surprises. In addition, we found evidence that growth is negatively associated with application levels of reports (partially supported). Thus, report existence, report count and application level results largely confirm each other. Finally, the authors tested the effect of sustainability reporting on firm performance, which did not produce significant results. Thus, in the aviation industry, sustainability reporting does not play a significant role in enhancing firm performance.Practical implicationsFirst, the findings show that larger and highly leveraged aviation firms can reduce agency and legitimacy costs through sustainability reporting. Surprisingly, the same assumption did not hold for ownership structure as the firms with diffused ownership base tend not to publish sustainability reports. Thus, boards are advised to establish and improve monitoring mechanisms in these types of firms. Second, although the number of aviation companies publishing separate sustainability reports has increased significantly over the years, almost half of the companies are not still producing sustainability reports. Hence, if the aviation industry believes the merits of engaging in sustainability issues and sincerely desires to enhance its sustainability reporting practices, the authors can suggest the following initiatives. Boards might encourage companies to incorporate sustainability issues into company operations by assigning the necessary financial and human resources. The boards might also establish a separate sustainability committee or department, which could focus on sustainability issues and reporting practices. Regulatory bodies could also encourage aviation companies to act in a socially and environmentally responsible manner by proposing legal requirements and providing guidance.Social implicationsRelevant civil organisations and environmental activists might undertake more active roles to enhance awareness of sustainability issues in the aviation industry.Originality/valueMost of the prior studies did not focus on standalone GRI-based sustainability reports, and they were conducted on limited samples and not the aviation industry in particular. This study aims to fill these gaps empirically by establishing testable hypotheses and attempting to demonstrate the validity of theoretical relationships in a wide range of data and among aviation companies worldwide. In this sense, this study is unique in what it undertakes. This study also tests whether sustainability reporting impacts firm value in the aviation industry which, to the best of the authors’ knowledge, has not been examined in prior studies to this extent.