The impact of sustainability reporting quality on firm market value according to GRI standards: A research on BIST

The purpose of this study is to examine the relationship between the sustainability reporting quality of companies and also the economic, environmental and social dimension quality of these reports and the firm market value. In this study, sustainability reports of 32 companies traded on Borsa Istanbul that published sustainability reports within the scope of GRI Standards in the 2017-2021 period were used. The criteria related to sustainability reporting quality and the economic, environmental and social dimensions quality of this reports were determined by scoring with the content analysis method. Scoring was carried out by taking into account the principles defined in the GRI Standards to determine report quality. The study investigates the determinants of firm market value by using value relevance analysis. The effects of variables accounting data and sustainability reporting quality on the firm value were determined by panel data analysis. The results of the analysis show that the book value per share, the sustainability reporting quality and the quality of the economic, environmental and social dimensions of the reports have significant positive effects on the firm market value. Sustainability reporting quality plays a decisive role in stakeholder's decision-making process. Accordingly, managers can make strategic decisions with the aim of increasing the firm market value and investor's confidence by improving the quality of the sustainability report. Increasing the quality of sustainability reporting through strong regulations and incentives for the establishment of global standardization studies and audit mechanisms for sustainability reporting can increase the competitiveness and market value of firms. Keywords: Sustainability, Sustainability Reporting Quality, GRI, Value Relevance