摘要： The formation of financial bubbles and their eventual crash are given an explanation in terms of the investors associated opinions dynamics. Indeed the existence of anticipation, either positive or negative about a given market, is shown to thwart the otherwise market efficiency. The underlying model accounts for collective anticipation combined with individual choices. For balanced anticipations the market is found to be efficient. However, for prevailing optimistic anticipation a bullish dynamic is produced even though most agents have bearish private information. Nevertheless, a limit is found to the bubble growing turning it at once into bearish. Moreover, a drastic shift in the collective anticipation maylead to a huge shift in the market trend generating a crash. S. Galam, Sociophysics, A Physicist's Modeling of Psycho-political Phenomena, Springer (2012) J. V. Andersen, I. Vrontos, P. Dellaportas and S. Galam, "Communication impacting financial markets", submitted Y. Biondia, P. Giannoccolob and S. Galam, "Formation of share market prices under heterogeneous beliefs and common knowledge", Physica A 391 (2012) 5532–5545 S. Galam, "Market Efficiency, Anticipation and the Formation of Bubbles-Crashes", Hyperion International Journal of Econophysics & New Economy, V5 (2012) 193-210

个人简介： Serge Galam, Senior Scientist at the National Center for Scientific Research (CNRS), is a world-renowned French theoretical physicist specialized in disordered systems. Thirty four years ago he envisioned and initiated sociophysics, which is today a flourishing international field of research. Besides contributions in condensed matter and statistical physics he has produced a series of founding models to investigate voting in hierarchical systems, group decision making, the stability and fragmentation of alliances among countries, minority opinions spreading, rumors phenomenon, terrorism, and opinion dynamics under the influence of contrarians and inflexibles. He has been able to predict a few national voting outcomes using his models. Beginning 2014 he joined the CEVIPOF, Centre for Political Research at Sciences Po, Paris, becoming the first physicist there.