Could consumers be "rational"? A multidisciplinary perspective - The author analyzes the "rationality" of purchase. The study considered in a critical perspective the hypothesis of a consumer more critical and selective (shared by sociology and marketing) using the tests on the bias of cognitive psychology and economics. The data shows the gap between the performance that consumers give to themselves and conduct real. The hypothesis of a selective consumer appears fogged by guidelines for decision making in which traditional guidelines remain as strong price sensitivity, and the emergence of new cohorts of stimulation on the customer as the framing about "quality". In conclusion, it seems that the hypothesis of a multidisciplinary approach is beneficial in terms of heuristic.
Keywords: Bias, decision making, consumer, rationality, framing.