Physics of fashion fluctuations

We consider a market where many agents trade different types of products wi th each other. We model development of collective modes in this market, and quantify these by fluctuations that scale with time with a Hurst exponent of about 0.7. We demonstrate that individual products in the model occasion ally become globally accepted means of exchange, and simultaneously become very actively traded. Thus collective features similar to money spontaneous ly emerge, without any a priori reason. (C) 2000 Elsevier Science B.V. All rights reserved.