Thread by @pmarca

"An Availability Cascade is a self-reinforcing process of collective belief formation -- an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse."

"The driving mechanism involves a combination of informational and reputational motives: Individuals endorse the perception partly by learning from the apparent beliefs of others, and partly by distorting their public responses in the interest of maintaining social acceptance."

"Availability Entrepreneurs -- activists who manipulate the content of public discourse -- strive to trigger Availability Cascades likely to advance their agendas."

"Availability Cascades are mediated by the Availability Heuristic, a pervasive mental shortcut whereby the perceived likelihood of any given event is tied to the ease with which its occurrence can be brought to mind."

"The probability assessments we make as individuals are frequently based on the ease with which we can think of relevant examples."

"This heuristic interacts with social mechanisms to generate Availability Cascades -- through which expressed perceptions trigger chains of individual responses that make these perceptions appear increasingly plausible through their rising availability in public discourse."

"Availability Cascades can generate persistent social availability errors -- widespread mistaken beliefs grounded in interactions between the availability heuristic and the social mechanisms we describe."

"The resulting mass delusions may last indefinitely, and they may produce wasteful or even detrimental laws and policies."

"An Availability Cascade subsumes two of the special cascades that have recently received considerable attention in the social sciences: Informational Cascades and Reputational Cascade."

"An Informational Cascade occurs when people with incomplete personal information on a particular matter base their own beliefs on the apparent beliefs of others."

"Suppose that the words and deeds of certain individuals give the impression that they accept a particular belief. In response to their communications, other individuals, who lack reliable information, may accept that belief simply by virtue of its acceptance by others."

"The transformation of the distribution of beliefs can take the form of a cascade, known also as a bandwagon or snowballing process."

"Under the right conditions, many or most of the society's members, potentially even all, will end up with essentially identical beliefs, which may well be fanciful."

"In the case of a Reputational Cascade, individuals do not subject themselves to social influences because others may be more knowledgeable. Rather, the motivation is simply to earn social approval and avoid disapproval."

"In seeking to achieve their reputational objectives, people take to speaking and acting as if they share, or at least do not reject, what they view as the dominant belief."

"If a particular perception of an event somehow appears to have become the social norm, people seeking to build or protect their reputations will begin endorsing it through their words and deeds, regardless of their actual thoughts."

"As in the informational case, the outcome may be the cleansing of [differing] perceptions, arguments, and actions from public discourse."

"Reputational and Informational Cascades are not mutually exclusive. Ordinarily, they exhibit interactions and even feed on one another. The resulting composite process, which is generally triggered by a salient event, is what we are calling an Availability Cascade."

"Social agents who understand the dynamics of Availability Cascades and seek to exploit their insights may be characterized as Availability Entrepreneurs."

"Located anywhere in the social system, including the government, the media, nonprofit organizations, the business sector... these entrepreneurs attempt to trigger Availability Cascades likely to advance their own agendas."

"Availability Entrepreneurs attempt to spark Availability Cascades by fixing people's attention on specific problems, interpreting phenomena in particular ways, and attempting to raise the salience of certain information."

"The Availability Heuristic is frequently amplified by socially shaped informational cues and reputational incentives. People often believe something because others appear to believe it; or they feign conviction to avoid reputational harm."

"The informational and reputational processes that shape public discourse feed on one another. Under the right conditions, they generate availability cascades that spread and worsen misperceptions. The perceived collective wisdom may bear little, if any, relation to reality."

"Availability Entrepreneurs try to trigger Availability Cascades likely to advance their causes. They focus attention on isolated events, select information to support their interpretations, and make anyone who questions their objectives appear ignorant, duped, or depraved."

"Availability Cascades are by no means new, but modem communications enable them to gather momentum and overwhelm governments far more rapidly than was possible in the past."

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