Abstract:
The purposes of this research were (1) to study capital structure, (2) to compare capital
structure between listed companies on the Stock Exchange of Thailand in the SET100 index and
companies listed on the Market for Alternative Investment (MAI), and (3) to investigate capital
structure determinants of listed companies on the SET100 and on the MAI. The samples used in this
research comprised of 51 listed companies on the SET100 index from 2013 to 2015, 97 SET100
listed companies in 2015, 58 companies listed on the MAI from 2013 to 2015, and 97 listed
companies on the MAI in 2015. The statistics used to analyze the data included mean, standard
deviation, Independent Sample t-test, Pearson Product Moment Correlation Coefficient and
Multiple Linear Regression at the statistically significant level of 0.05.
The results of the study showed that from 2013 to 2015 listed companies on the SET100
had the mean of book leverage ratio and the mean of market leverage ratio at 28.15% and 20.16%
respectively, while listed companies on the MAI indicated the means of 8.19% and 6.71% of book
leverage ratio and market leverage ratio respectively. Additionally, in 2015 whereas the SET100
listed companies had the mean of book leverage ratio at 27.94% and the mean of market leverage
ratio at 18.58%, the MAI listed companies showed the means of those ratios at 7.89% and 5.61%
respectively. Also, the findings indicated that the SET100 listed companies had a higher leverage
ratio from 2013 to 2015 and in 2015 than the MAI listed companies did, at the statistically
significant level of 0.05.
In addition, the results revealed that from 2013 to 2015 firm size, profitability, non-debt
tax shields and debt service coverage had an influence on the leverage ratio of the SET100 listedcompanies, whereas firm size, fixed asset, and debt service coverage had an impact on the leverage
ratio of the MAI listed companies. It was also found that in 2015, firm size, profitability, and debt
service coverage had an impact on the leverage ratio of the SET100 listed companies, while firm
size had an influence on the leverage ratio of the MAI listed companies at the statistically
significant level of 0.05.