Modeling Speculative Bubbles in Tehran Stock Exchange Considering Social and Psychological Dynamics

Stock market is one of the important markets in any economy and a good understanding of it is necessary for policy making both in individual and governmental levels. One of the phenomena seen in asset markets is bubble. Several works have been done about bubbles in Tehran Stock Exchange (TSE), but no one has developed a new theoretical model. Almost all of the atudies have used the mainstream approach, conventional econometric methods or an accounting approach. To consider the social and psychological dynamics, we applied Agent-based Computational Economics (ACE). The model is validated with the time series of overall index of TSE and the results are satisfactory. We showed that the presence of uncertainty about future fundamentals on one hand, and heterogeneous expectation and social and psychological dynamics , on the other hand can explain how a bubble in TSE is formed. The model developed here is simple and basic, and therefore can be a good basis for more full-fledged models of different markets. The results also show that the speed of learning has increased through time.