An investigation of crash avoidance in a complex system

Complex systems can exhibit unexpected large changes, e.g. a crash in a financial market. We examine the large endogenous changes arising within a non-trivial generalization of the minority game: the grand canonical minority game. Using a Markov-Chain description, we study the many possible paths the system may take. This ‘many-worlds’ view not only allows us to predict the start and end of a crash in this system, but also to investigate how such a crash may be avoided. We find that the system can be ‘immunized’ against large changes: by inducing small changes today, much larger changes in the future can be prevented.