title: Modeling financial markets by self-organized criticality.
abstract: We present a financial market model, characterized by self-organized criticality, that is able to generate endogenously a realistic price dynamics and to reproduce well-known stylized facts. We consider a community of heterogeneous traders, composed by chartists and fundamentalists, and focus on the role of informative pressure on market participants, showing how the spreading of information, based on a realistic imitative behavior, drives contagion and causes market fragility. In this model imitation is not intended as a change in the agent's group of origin, but is referred only to the price formation process. We introduce in the community also a variable number of random traders in order to study their possible beneficial role in stabilizing the market, as found in other studies. Finally, we also suggest some counterintuitive policy strategies able to dampen fluctuations by means of a partial reduction of information.
authors.affiliation: Dipartimento di Economia e Impresa - Universitá di Catania, Corso Italia 55, 95129 Catania, Italy.
authors.forename: Alessio Emanuele
authors.initials: AE
authors.lastname: Biondo
authors.affiliation: Dipartimento di Fisica e Astronomia, Universitá di Catania and INFN sezione di Catania, Via S. Sofia 64, 95123 Catania, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pluchino
authors.affiliation: Dipartimento di Fisica e Astronomia, Universitá di Catania and INFN sezione di Catania, Via S. Sofia 64, 95123 Catania, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rapisarda