Risk aversion in financial decisions : A nonextensive approach ∗

The sensitivity to risk that most people (hence, financial operators) feel affects the dynamics of financial transactions. Here we present an approach to this problem based on a current generalization of Boltzmann-Gibbs statistical mechanics. An important question in the theory of financial decisions is how to take into account those psychological attitudes of human beings that produce significant deviations from the ideally rational behavior. It is not by chance that a new discipline that focus on such questions , behavioral finance, is starting to gain universal recognition. In fact, Daniel Kanheman from the Psychology Department at Princeton University has been awarded (together with Vernon Smith) the 2002 Nobel Prize in Economics " for having integrated insights from psychological research into economic science, especially concerning human judgment and decision-making under uncertainty " [1]. Indeed, one of the human attitudes with important consequences in financial decision making is the risk aversion (attraction) that most people feel when they expect to gain