This research aims to study the relationship between tax planning & performance and the stock prices & dividend payments of companies listed on the Stock Exchange of Thailand SET100 group. It was conducted by collecting information from financial statements annual reports and the information registration forms (Form 56-1) of 69 companies from 2015 to 2019. Descriptive statistics and inferential statistics were used for data analysis including correlation analysis and multiple regression analysis. The study results show that the return on equity ratio (ROE) book value per share (BV) and earnings per share (EPS) ratio positively correlated with the stock prices. The corporate income tax rate to total assets (TAX/ASSETS) the return on total assets (ROA) the return on equity (ROE) and the book value per share (BV) ratio were positively correlated with the dividend yield (DY) ratio. The earnings per share (EPS) ratio had a negative correlation with the dividend yield (DY) ratio and the effective corporate income tax (ETR) ratio had a positive correlation with the dividend payout ratio (DP) with a statistical significance at 0.01 and 0.05 levels.

This research aimed to study the relationship between Corporate Governance Social Responsibility and Profitability of 56 companies related to the agriculture and food industry and listed on the Stock Exchange of Thailand. Data was collected for 2015 to 2020 and analyzed using descriptive statistics such as frequency percentage mean and standard deviation. Likewise this research also used inferential statistics including Pearson’s Correlation Analysis and Multiple Regression Analysis. The findings were Corporate Governance; Proportion of Independent Director (PID) had positively correlated with Profitability including the Return on Total Assets (ROA) the Return on Equity (ROE) and the Gross Profit Margin (GPM). The correlations were statistically significant at 0.01 and 0.05 levels. Besides Corporate Social Responsibility; the Environmental Social and Governance (ESG) and the Disclosure of Corporate Social Responsibility Activity (DCSRA) had also positively correlated with Profitability including the Return on Total Assets (ROA) the Return on Equity (ROE) and the Gross Profit Margin (GPM). The correlations were statistically significant at 0.01 and 0.05 levels.

This study aimed to investigate the relationship between corporate governance and financial ratio with the performance of companies listed on the stock exchange of Thailand with an excellent score. The data were collected from annual registration statement (Form 56-1) of 191 companies from 2016 to 2020. Descriptive statistics such as mean percentage standard deviation and Inferential statistics such as Pearson’s Correlation Coefficient and Multiple Regression Analysis were used to examine the relationship. The results showed that 1) Corporate Governance namely Board size the ratio of independent director and Managerial Ownership positively corelated with firm performance. 2) Leverage Ratios (Financial Ratio) namely Debt to asset ratio and Debt to equity ratio negatively corelated with firm performance but Interest coverage ratio positively corelated with performance

The objective of this research is to study the techniques of profit quality analysis and the consistency of the profit quality with different profit quality analysis techniques; and to compare profit sustainability between large companies and small companies of the industrial energy and utilities group and the petrochemical and chemical group. The data is collected from financial statements and data entry forms (Form 56-1) from 2012 to 2018. A total of 47 companies are analyzed using descriptive statistics including mean and standard deviation; and inferential statistics including multiple regression analysis and analysis of the average difference between 2 groups The research found that in the analysis of the profit quality consistency in all 4 methods there were only 13 companies in the energy and utilities group with consistent quality of profits accounting for 39.39%; and 20 with inconsistent results accounting for 60.61%. In the petrochemical and chemical group there was only 1 company with consistent quality in all 4 methods representing 7.14%; and 13 companies with inconsistent quality representing 92.86%. In addition when comparing the profit sustainability between large companies and small companies it was found that there was no statistical difference in profit sustainability (sig = 0.305> 0.05). When comparing the profit sustainability between energy and utilities group and the petrochemical and chemical group it was found that petrochemical and chemical companies had a higher profit sustainability than the energy and utilities group at statistical significance of 0.01 (sig = 0.009 <0.01).

The objective of this research is to study the companies listed on the Stock Exchange of Thailand Property and Construction Group on the relationship between corporate governance; namely the percentage of shares held by executives proportion of independent directors size of the board of directors management responsibilities of the chairman and the proportion of attendance at board meetings and 1) the operating result i.e. the return on total assets return on equity return on sales and earnings per share and 2) tax planning including the ratio of tax expenses to accounting profits before income tax and tax rate per total asset. The secondary data collected from the financial statements and the registration statement (Form 56-1) from year 2014 to 2018 in total of 71 companies is analyzed using descriptive statistics including mean and standard deviation and inferential statistics such as correlation analysis and multiple regression analysis. The research results showed that corporate governance including the shareholding percentage held by management management responsibilities of the chairman and the proportion of attendance at the Board meetings has a positive relationship with tax planning (Tax rate to total assets) with statistical significance at the level of 0.01 and 0.05. There is also a positive relationship between the operating results including the return on total assets and tax planning (Tax rate to total assets) with statistical significance of 0.01.