To the extent that social norms enter into this account it is as a constraint on the feasible set of available alternatives. That is, social norms affect the incentives available to the actor, affect the values of the different alternatives. Sunstein argues for an alternative conception of individual decision making that gives a larger role to social norms and directly challenges the standard conception of rational decision making. He builds his account on the arguments of Laurence Lessig who has developed a theory of the expressive function of law. On Lessig's account law and norms express fundamental values and beliefs about how people think social life ought to be organized.
Social norms influence reputational effects and consequences for self-conception.
For Sunstein this leads to the following conclusions about the ways in which we analyze individual decision making, conclusions that imply changes in the standard rational choice conception. Therefore, we should give greater attention in our research to questions of preference formation and change. Second, individual choice is a function of social context. Third, some of the most important social norms in a society relate to basic values of fairness and justice. Therefore, we should incorporate attitudes about justice and fairness in our conceptions of individual decision making.