The Black Swan

Rare, extreme, unpredictable events — Black Swans — dominate history, yet our models, plans, and predictions are built on the assumption of normal distributions and exclude them.

• Every swan ever observed in Europe was white — building centuries of unshakeable certainty that all swans were white. One trip to Australia destroyed it entirely.
• The 2008 financial crisis: every major risk model in every major bank assigned it a probability approaching zero.
• The internet, World War I, and the fall of the Soviet Union were all events that no serious model predicted — yet each transformed the world more than all the predicted events combined.