ความสัมพันธ์ระหว่างการกำกับดูแลกิจการกับคุณภาพกำไรของบริษัทจดทะเบียนในตลาดหลักทรัพย์แห่งประเทศไทย

Abstract

This independent study aimed to investigate the relationship between corporate governance and earnings quality of the companies listed on the Stock Exchange of Thailand (SET). The study was conducted by comparing the earnings quality of those companies listed on the SET. The samples were the companies whose corporate governance was assessed by the Corporate Governance Report of Thai Listed Companies project (CGR) and the ASEAN Corporate Governance Scorecard (ACGS), or that participated in Thailand’s Private Sector Collective Action Coalition Against Corruption project (CAC). A total of 1,990 data entries on stock price, dividend per share, and earnings per share of those companies listed on the SET as obtained from the SETSMART database in 2013 –2019 (B.E 2556-2562) were collected. These acquired data were, then, analyzed by using the multiple regression method with the Easton and Harris’s Return Model (1991). To examine the relationship between the corporate governance and earnings quality, values of the coefficient of determination (Adjusted R2 ), the Akaike’s Information Criterion (AIC), and the Bayesian Information Criterion (BIC) obtained from the samples listed in each assessment institute or project as mentioned earlier were compared and discussed. According to the study, the results revealed that values of the coefficient of determination (Adjusted R2 ) of the companies listed in the CGR (or participated in the CAC) with a high level of corporate governance scores were higher than the companies (that did not participate in the CAC with a low level of corporate governance scores. This finding correlated to the results of the analysis of AIC and BIC values, which indicated that the AIC and BIC values of the companies listed in the CGR (or participated in the CAC) with a high level of corporate governance scores were lower than the companies (that did not participate in the CAC) with a low level of corporate governance scores. Consequently, it could be concluded that the earnings of the companies listed in the CGR (or participated in the CAC) with a high level of corporate governance scores could reflect their stock prices in a better way than the companies (that did not participate in the CAC) with a low level of corporate governance scores did. In the meanwhile, the findings presented that the Adjusted R2 value of the companies enlisted in the ranking of the ACGS project was lower than the value of the companies that were not enlisted in the ranking. This result correlated to the BIC value but was different from the AIC value. Therefore, it could not say that the companies enlisted in the ranking of the ACGS project could have better earnings quality than those that were not enlisted in the ranking list. However, the results of this study could benefit the investors in a way that they could make use of information obtained from the corporate governance assessment for their decision-making. An agent that was responsible for the corporate governance could apply this study as a guideline to improve the corporate governance criteria to be more effective and appropriate.