ABSTRACT

All financial crises recorded throughout history have one thing in common: they allow financial authorities to quickly take resolutions and/or measures to restore confidence in the system, to at most appear to constitute a paradigm shift or a change in the economic model. Economists and/or financiers are failing because they continue to reason and model through the rationality of individuals and the hypothesis of market efficiency when it would be more appropriate to use the paradigm proposed by behavioural theory. Thus, according to the research conducted in psychology, most of the players in the financial markets are victims of financial illusions. Decision-making is done in a given environment, in a situation of asymmetrical information, market flaws and strategic or opportunistic behaviour. The challenge of behavioural finance research is to be able to establish a bridge between the individual approach and the collective approach.