Availability Cascade

In an Availability Cascade, beliefs become widely accepted through frequent public repetition. This phenomenon, crucial in shaping public discourse, is driven by psychological factors and media influence, extending its reach beyond cultural limits.

Definition and Concept

  • Availability Cascade: A self-reinforcing process where a collective belief gains more plausibility through increased public repetition and exposure.
  • This phenomenon is part of social psychology and behavioral economics.

Etymology and Origin

  • The term “Availability Cascade” was coined by Cass Sunstein and Timur Kuran in the 1990s.
  • It builds on the concept of “availability heuristic” by Amos Tversky and Daniel Kahneman.

Foundational Mechanics

  • Informational Influence: People assume that if many others believe something, there must be some truth to it.
  • Reputational Motives: Individuals may propagate a belief to align with perceived social norms or authority figures.
  • Cognitive Shortcuts and Heuristics: Reliance on mental shortcuts allows rapid formation and spread of beliefs.

Key Components

  • Trigger Event: An incident or information that initiates the cascade.
  • Media Amplification: Media plays a crucial role in disseminating the initial information, contributing to its repetition and visibility.
  • Public Endorsement: When influential figures or the general public adopt and spread the belief.
  • Emotional and Sensational Content: Tendency for emotionally charged information to be more readily propagated.

Role of Technology and Social Media

Modern technology and social media platforms significantly accelerate and expand the reach of availability cascades.

Impact on Policy and Decision-Making

Availability cascades can significantly influence public policy and decision-making, especially by distorting perception of risks.


  • Financial Markets: Rumors about a company can lead to significant stock price movements, regardless of the rumor’s factual basis.
  • Health Scares: Misinformation about health risks can lead to widespread public concern, influencing behaviors and policies.

Interconnected Concepts

  • Confirmation Bias: The tendency to seek, interpret, and remember information in a way that confirms preexisting beliefs, reinforcing the cascade.
  • Groupthink: The practice of thinking or making decisions as a group in a way that discourages creativity or individual responsibility.