Imitation and stability in a stock market

This paper explores a continuous version of a stock market model in which an imitation component of agent behaviour is introduced. It is assumed that the time variations of the intensity of proposed transactions made by each agent in the stock market is decomposable into a component determined by the speculative attitude of the agent and by an imitation pattern of the behaviour of other agents. It is shown that imitation generates instability, which confirms the wisdom of some rules which discourage it.