The aim of this dissertation is to study the bubbles in the economy. There are two separated studies which are 1) “Testing the bubbles and the crashes of the asset prices: The evidence from the southeast Asian countries.” and 2) “Can government bond replace rational bubbles? The empirical investigation on Singapore and Thailand.” combined in this dissertation.  For the long period of time, many economists try to find the detector for the existense and the crashes of the bubble. However, many of econometric models might distinquish the explosive ...