Norm Compliance : The Contribution of Behavioral Models

In the last few years, self-interest and opportunism have become the target for criticism from behavioural economics theorists who urge the introduction of a more complex - and hopefully a more realistic - view of economic agents' motivations. A number of models of choice have devised based on the idea that the evidence about how people play, for example, ultimatum, dictator and public goods games can be explained in terms of preferences for equity and/or reciprocity. Our question is whether these models could be applied also to the case in which a norm of fairness is explicitly introduced in the game, for example by letting the players choosing it behind a veil of ignorance. We ask under what conditions people who contributed to the choice of the norm actually comply with it even when compliance is not compatible with the pursue of their self interest and when the norm cannot be enforced. To deal with this problem one must give up with the standard self-interest-based model of rational agent and move toward more sophisticated models, based on the idea that agents are characterized by a more complex motivational system. But which theory captures the motivations involved in this kind of problems? In the paper we try to answer this question by considering the results of an experiment based on a one-shot game, called "the Exclusion Game", which is characterised by: (i) players may agree on a norm of fairness behind a veil of ignorance (ii) players' compliance with the norm affects also the wellbeing of individuals who does not participate to the game but who share the norm (iii) the norm is not enforced by any kind of sanction. After showing that the mostly well known behavioural models fail in explaining the relevant evidence, we discuss two theories, the "normative expectations" and "conformist preference" theories, that give a better understanding of norm compliance