A black swan event is a rare, unpredictable occurrence that has a massive impact and is often rationalized with hindsight as if it were predictable. The concept was popularized by Nassim Nicholas Taleb, who described such events as extreme outliers that lie outside normal expectations and have significant consequences in history, finance, science, and technology
. Key characteristics of a black swan event include:
- Rarity: It is so unusual that its possibility is unknown or ignored before it happens.
- Extreme impact: The event causes major disruptions or changes.
- Retrospective predictability: After the event occurs, people try to explain it and make it seem foreseeable, even though it was not predicted beforehand
Examples of black swan events include the 2008 financial crisis, the COVID-19 pandemic, and the September 11 terrorist attacks
. These events challenge existing beliefs and models because they fall outside typical risk assessments and forecasting tools, revealing vulnerabilities in systems and prompting changes in worldview or regulation
. In summary, a black swan event is an unforeseen, high-impact event that reshapes understanding and systems, often only recognized as significant after it occurs.
