Rational Speculative Bubbles in the Thai Stock Market: Econometric Tests and Implications

Understanding of factors like economic fundamentals or bubbles that normally determine the returns of stock in any emerging market such as the Thai stock market is essential for academic, investment planning and public policy reasons. An empirical study of the existence of rational speculative bubbles in the Thai stock market is undertaken by using the Weibull Hazard model. The conventional Weibull Hazard model is used as a benchmark model for other speculative bubble models. Empirical results suggest the presence of rational speculative bubbles in the Thai stock market, especially during the pre-crisis period. While rational speculative bubbles were not present immediately after the post-crisis period, some were observed a few years after the crisis. A possible explanation for such a result concerning rational speculative behaviour and bubbles in the emerging stock markets could be attributed to the presence of market imperfections in emerging stock markets, requiring institutional and policy developments to ensure efficient operation of the stock market.