Cascades, Tipping Points, and Riots
Last year, I read some interesting work by Duncan Watts about riot theory: he suggested that people have different minimum thresholds—inherently and socially—before they’re willing to riot. The idea is that there’s a formula of circumstance and number of people already rioting that will incite newcomers to join the rioters. In the context of networks, this is analogous to information cascades and the ‘tipping point’; potential rioters assess the circumstance based on the fact that other people are rioting (information cascades) and will join if a critical mass of people are already rioting (tipping point). Michael Gross discusses these phenomena in his article, “Why Do People Riot?”
Michael Gross first analyzes riots based on the information cascade model, saying, “people… just followed the information cascade model, basing their decisions on the decisions made by others before them.” In essence, people decided that if others were rioting, it must be a good idea to riot, too. The true prudence of rioting is irrelevant because people were basing their decisions on the actions of others, not on the independent facts. It makes intuitive sense that there are people who will riot in conjunction with others but not by themselves, and information cascades are the social mechanism by which that phenomenon occurs.
Gross also discusses the concept of a tipping point. He quotes Katharina Zweig, who says, “If a potential participant gets the feeling that the crowd is going to be huge, she will go unnoticed. If it is too small, her risk of being caught is too high.” Obviously, each person’s assessment of risk will feature different numbers and ranges of acceptability. As such, each person has a requisite number of rioters who must be in motion before she joins the fray. And as each subsequent person joins, others—who exist on the margin—are newly incentivized to join. As such, the “tipping point” is the number of rioters who initiate that positive feedback loop, because once the crowd starts to grow, it’s off to the races.
The concepts of information cascades and the tipping point form an interrelationship that provides a holistic description of riots. People emulate the actions of the group, and this can be a rational choice, despite being a potentially imprudent action. And the creation of a group is predicated on surpassing a critical mass of people—a tipping point—after which a positive feedback loop increases the size of the mob.
Or click here to read Gross’ paper.