A theory of fads, fashion, custom, and c

A theory of fads, fashion, custom, and cultural change as informational cascades Bikhchandani, S., Hirshleifer, D., & Welch, I. (1992). A theory of fads, fashion, custom, and cultural change as informational cascades. Journal of political Economy, 100(5), 992-1026.

4 theories for social confirmity: ) sanctions on deviants,2 (2) positive payoff externalities,3 (3) conformity preference,4 and (4) communication.

Don’t seem as relevant to a linguistic context as those cited in the next paper: primacy (the first variant of some norm tends to persist), social status (norms are often introduced by individuals with higher social capital) [13], minimization of joint effort [6], as well as mechanisms like accommodation [15] and audience design [4]

An informational cascade occurs when it is optimal for an individ- ual, having observed the actions of those ahead of him, to follow the behavior of the preceding individual without regard to his own information

How well-suited are information cascades to a theory of linguistic change? There is clearly lots of opportunity for assessment of others’ judgments, and lots of ambiguity in knowing the 

However, linguistic communication is not primarily about utility, or at least not directly. It’s more about social positioning. 

Our contribution is to model the dynamics of imitative decision processes as informational cascades

The problem with cascades is that they prevent the aggregation of information of numerous individuals. Ideally, if the information of many previous individuals is aggregated, later individuals should con- verge to the correct action. However, once a cascade has started, actions convey no information about private signals; thus an individual’s action does not improve later decisions.(998-999) This is interesting from a linguistic perspective, because norms are normative. The cascade may provide the “objective” index of the norm. 

Rogers and Shoemaker (1971) summarize research on the ability of outsiders (or “change agents”) to bring about the adoption of desir- able innovations within communities. They offer the general proposi- tion that “change agent success is positively related to his efforts in increasing his clients’ ability to evaluate innovations” (p. 247).

A major result of this section is that a cascade eventually begins.

s. While order is exogenous in the model, it is plausible that the highest-precision individual decides first. Con- sider a more general setting in which all individuals have the choice to decide or to delay, but there is a cost of delaying decision. All individuals have an incentive to wait in the hope of free-riding on the first to decide. However, other things equal, the cost of deciding early is lowest for the individual with the highest precision. The fashion leader model applies to situations in which a veteran performs a task with novices. If an experienced individual acts first, others frequently imitate (1002)

there’s probably some counter-cascade force too. (Like in lecture!)

The social cost of cascades is that the benefit of diverse information sources is lost

A limitation of this model for application to linguistic phenomena is apparent in the article’s discussion of fads. 

Social positioning, relying on previously-established indexical significance

Also highly non-sequential.