Credit Rating and Cost of Capital

The competitive business environment is growing, accordingly, companies are forced to compete with various national and international factors and expand their activities through their new investments. To make these investments, they need financial resources. The importance of accessing useful information for decision-making is important, as it is considered an investor right. Credit rating is useful information for investment decision-making. This study examines the relationship between credit rating and the cost of capital. Its purpose is to examine whether an increase in credit rating leads to an increase in the cost of equity and a decrease in debt costs or not. Because of the narrow background of ranking institutions in Iran and the reluctance of the companies toward the ranking system, a general ranking model is commonly used to determine the rank of the investigated companies.
This study examines a sample of 142 companies listed on the Tehran stock exchange from 2014 to 2020. The companies were selected through a systematic elimination process. The credit rating for each company was measured using the Emerging Market Credit Scoring Model. This rating was then adjusted in three steps: (1) considering the company's vulnerability to exchange rate fluctuations, (2) assessing the degree of credit rating of the industry, and (3) evaluating the company's competitiveness within the industry. A dummy variable was used to indicate an increase or decrease in credit rating from the previous year, where an increase takes the value of one and a decrease takes the value of zero. The cost of debt was calculated by dividing the interest expense in year t+1 by the average debt during years t and t+1, while the cost of equity was calculated by dividing net profits by the equity market value in year t. We used multiple regression with the Generalized Least Squares (GLS) method.
According to the obtained results, there is a positive relationship between credit ratings and equity costs, and any increase in credit ratings can reduce the costs of debts.
Based on the achieved results, there appears to be a positive correlation between credit ratings and the cost of equity. Furthermore, any increase in credit ratings has the potential to decrease the cost of debt. As a result, an increase in credit rating may lead to an increase in profits, because debt costs decrease and equity costs are affected. This subsequently influences investment decisions. Additionally, the risk of a company can have an impact on its expected rate of return. These findings align with Chen, Chen, Chang, & Yang (2013) as well as Kissgen and Esrahan (2010). It is worth noting that the Emerging Market Model has been validated by comparing its rankings to those announced by the rating agencies. This model takes into account both quantitative and qualitative factors. Therefore, we suggest that rating agencies consider utilizing these results as a guideline for ranking purposes.