The relationship between Sustainability Reporting and corporate financial performance is overlapping and multifaceted and it has been an interesting issue for both academics and professionals since the beginning of the millennium. Studies have found divergent results on this relation and the industrial differences are omitted in many papers. Moreover, studies considering developing countries are scarce. The purpose of this study is to shed light on the relationship between sustainability reporting and firm performance in a developing country context. The impact of sustainability reporting is investigated using pooled ordinary least square (OLS) method for panel data regression through two models based on Tobin’s Q and ROA. A total of 920 observations for 46 companies with 3 different impact levels based on their environmental effect and 5-year quarterly panel data between 2016–2020. The research used data from Borsa Istanbul (Istanbul Stock Exchange) and also independent variables such as leverage, risk, size, current ratio, growth, sustainability reporting, and the environmental impact level of companies. The results showed that sustainability reporting has a significant positive impact on financial performance according to the ROA model, and a significant negative correlation between risk and financial performance according to both ROA and Tobin’s Q models. Considering the environmental impact of companies, the results also reveal a positive relationship between high impact companies’ sustainability reporting and short-term financial performance as ROA is an accounting-oriented measure that reveals the company’s short-term financial performance. Further research should investigate the impact of sustainability reporting in different markets based on the impact level of companies and the development degree of countries.

The impact of sustainability on corporate financial performance has been an important subject of both academic and professional debate since the 1990s. However, there is a lack of consensus in the literature, and studies from developing countries remain scarce. Accordingly, this study uses discriminant analysis to shed light on the variables that discriminate between sustainable and non-sustainable companies using the companies included in Borsa Istanbul (BIST100) (Istanbul Stock Exchange) and the Borsa Istanbul Sustainability Index for a three-year period. Financial and market variables are used in the analysis. Financial variables include the return on equity (ROE), return on assets (ROA), leverage ratios, and company size. The analysis also incorporates market variables such as alpha, beta, volatility, earnings per share, and the price to book ratio. The results show that the relationship between sustainability and performance is significantly influenced by the company size, leverage, volatility, and price to book ratio. The large companies are considered to be more sustainable as their commitment is well recognized. In this way, they attract more investors. Therefore, their stock prices are less volatile and achieve a better price to book ratio. They obtain easy access to external financing compared to companies considered to be non-sustainable. Moreover, they are less volatile in the market and better valued by investors.

Code of ethics has become a significant concept as regards to the business world. That is why occupational organizations have developed their own codes of ethics over time. In this study, primarily the compatibility classification of the accounting code of ethics belonging to the IFAC (The International Federation of Accountants) is carried out on the basis of the action plans assessing the levels of usage by the 175 IFAC national accounting organizations. It is determined as a result of the classification that 60,6% of the member organizations are applying the IFAC code in general, the rest 39,4% on the other hand, is not applying the code at all. With this classification, the hypothesis propounding that “The national accounting organizations in highly corrupt countries would be less likely to adopt the IFAC ethic code than those in very clean countries,” is tested using the “Corruption Perception Index-CPI” data. It is determined that the findings support this relevant hypothesis.