Some authors identify norms with observable, recurrent patterns of behavior.
Others only focus on normative beliefs and expectations.
Norms are efficient means to achieve social welfare (Arrow 1971; Akerlof 1976), prevent market failures (Jules Coleman 1989), or cut social costs (Thibaut & Kelley 1959; Homans 1961); norms are either Nash equilibria of coordination games or cooperative equilibria of prisoner’s dilemma-type games (Lewis 1969; Ullmann-Margalit 1977), and as such they solve collective action problems.
Akerlof’s (1976) analysis of the norms that regulate land systems is a good example of the tenet that “norms are efficient means to achieve social welfare”.
Yet even if a norm may fulfill important social functions (such as welfare maximization or the elimination of externalities), it cannot be explained solely on the basis of the functions it performs.
The simplistic functionalist perspective has been rejected on several accounts; in fact, even though a given norm can be conceived as a means to achieve some goal, this is usually not the reason why it emerged in the first place (Elster 1989a, 1989b).Beliefs, expectations, group knowledge and common knowledge have thus become central concepts in the development of a philosophical view of social norms.Paying attention to the role played by expectations in supporting social norms has helped differentiate between social norms, conventions, and descriptive norms: an important distinction often overlooked in the social science accounts, but crucial when we need to diagnose the nature of a pattern of behavior in order to intervene on it.Moreover, although a particular norm may persist (as opposed to emerge) because of some positive social function it fulfills, there are many others that are inefficient and even widely unpopular.Philosophers have taken a different approach to norms.Because of that, the issue of has been paramount in the social science literature.Moreover, since social norms are seen as central to the production of social order or social coordination, research on norms has been focused on the they perform.Like a grammar, a system of norms specifies what is acceptable and what is not in a society or group.And, analogously to a grammar, it is not the product of human design.In the literature on norms and conventions, both social constructs are seen as the endogenous product of individuals’ interactions (Lewis 1969; Ullmann-Margalit 1977; Vandershraaf 1995; Bicchieri 2006).Norms are represented as equilibria of games of strategy, and as such they are supported by a cluster of self-fulfilling expectations.