Sustainability accounting and reporting: An application at Borsa Istanbul

As a result of business activities, not only financial outcomes but also social and environmental consequences arise. Due to these outcomes, the concept of sustainability began to gain attention through various international studies and conferences starting from the 1970s. Today, it is expected that companies include social and environmental aspects in their reports alongside financial information, particularly through sustainability reports. In recent years, there has been a significant increase in the number of companies publishing sustainability reports both globally and in Turkey. The level at which companies achieve their social, environmental, and economic sustainability goals is assessed through their sustainability performance. This study aims to evaluate the corporate sustainability performance of two companies operating in the airline transportation sector. For this purpose, Multi-Criteria Decision-Making (MCDM) methods were utilized. The research consists of two main parts. Firstly, the corporate sustainability performance of airline companies listed in the Borsa Istanbul (BIST) Sustainability Index was analyzed using the TOPSIS method. As a result of the study, the relative success levels of the companies in terms of corporate sustainability performance were revealed. As a result of business activities, not only financial outcomes but also social and environmental consequences arise. Due to these outcomes, the concept of sustainability began to be discussed globally in various studies and conferences starting from the 1970s. Today, it is expected that companies include not only financial aspects in their reports but also social and environmental dimensions through sustainability reporting. Recently, the number of companies publishing sustainability reports has significantly increased both globally and in Türkiye. The extent to which companies achieve their social, environmental, and economic sustainability goals is evaluated through their sustainability performance. In this study, which aims to assess the corporate sustainability performance of two airline companies operating in the air transportation sector, Multi-Criteria Decision-Making (MCDM) methods have been utilized. The research consists of three parts: first, the corporate sustainability performances of airline companies listed in the BIST (Borsa Istanbul) Sustainability Index were examined using the TOPSIS method, and the results revealed their respective levels of success regarding sustainability performance. The findings of the study indicate that sustainability performance varies significantly between companies across different dimensions. According to the analysis, Turkish Airlines (THYAO) demonstrated consistently strong performance in the social sustainability dimension over all three years, maintaining a leadership position in this area. On the other hand, Pegasus Airlines (PGSUS) stood out in both environmental and economic sustainability, reaching near-ideal scores particularly in 2022 and 2023, highlighting the effectiveness of its corporate strategies in these domains. These findings show that companies tend to prioritize different aspects of sustainability, and their performance outcomes reflect these strategic orientations. The study contributes to the quantification, comparison, and evaluation of sectoral sustainability performance through data obtained via the TOPSIS method. In this respect, it emphasizes the importance of sustainability reporting and provides an original contribution to the literature by demonstrating how multi-criteria decision-making approaches can be effectively applied in empirical analyses.