The purposes of this research were 1) to study the effect of corporate governance on firm performance, 2) to examine the effect of corporate governance on competitive advantage, and 3) to find out the effect of competitive advantage on firm performance. The quantitative data consisted of 5-year longitudinal/panel data (2011- 2015). Only qualified companies listed in the Stock Exchange of Thailand (SET) were selected as population. The total of 203 shortlisted companies were good for 1,015 observations. The dummy variables derived from IOD corporate ...