Black swan theory

Black swan theory 

The black swan theory or theory of black swan events is a metaphor that describes an event that comes as a surprise, 
has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight. 
The term is based on an ancient saying that presumed black swans did not exist, until they were discovered in Australia in 1697, 
and it then became reinterpreted to mean an unforeseen and consequential event.


Identifying
Based on the author's criteria:

1 The event is a surprise (to the observer).
2 The event has a major effect.
3 After the first recorded instance of the event, it is rationalized by hindsight, as if it could have been expected; 
  that is, the relevant data were available but unaccounted for in risk mitigation programs. The same is true for the personal perception by individuals.


Deterministic chaotic dynamics reproducing the Black Swan Event have been researched in economics.
That is in agreement with Taleb's comment regarding some distributions which are not usable with precision, 
but which are more descriptive, such as the fractal, power law, or scalable distributions and that awareness 
of these might help to temper expectations. Beyond this, Taleb emphasizes that many events simply are without precedent, 
undercutting the basis of this type of reasoning altogether.

Taleb also argues for the use of counterfactual reasoning when considering risk.