Rationality, frames, and social influence. An on-line experimental test of the informative effects of law

This paper empirically tests whether law can have effects on the perception of risk associated to a specific behaviour. With this purpose we have carried out an on-line experiment in order to test two mechanisms through which law could exert this influence. According to the theory of the expressive function of law, compliance can be generated expressively, independently of deterrence and legitimacy. A particular case of the expressive effect of law is the informative effect. In this case, law can provide information about the damages (or benefits) of a particular behaviour. This information leads citizens to update their prior beliefs and thereby changes their behaviour. Under this view, the psychological mechanism which operates this change is rationality.

In previous work we have showed that law can effectively change individuals’ beliefs, but that the mechanism operating this change is more likely to be framing rather than rationality. In this paper we argue, first, that banning (or legalizing) a particular behaviour may activate a frame that favours conformism and social influence, thus leading individuals to adapt their beliefs to those which are dominant among their peers, and to raise (or lower) their perception of risk associated to that behaviour. Second, we carry out an on-line experiment with two control groups and four treatments to test our hypothesis. In the control groups we simply observe the perception of risk associated to some particular behaviour. In the treatments, the same perception is observed after giving the subjects information about the result of a vote to decide whether to ban or legalize the behaviour under consideration; the information about the result of the vote is altered in a controlled way. Finally, we discuss in detail the results and their possible implications for social sciences and for institutional design.