Black SwanComparison

Mediocristan vs Extremistan

Whenever you plan to «average» something. First classify the domain.

Axis	Mediocristan	Extremistan
Does one observation move the total?	No	Yes - often dominates it
Sample size logic	Works as expected	Lies - tail dominates
Examples	Height, weight, blood pressure	Wealth, virality, book sales

Example

Median tweet engagement tells you very little about how a viral tweet performs. Median startup revenue is meaningless - a handful of outliers explain everything.

Open the underlying concepts

MediocristanDomains where no single observation dramatically changes the total - physical attributes, repeating natural processes, well-bounded quantities.ExtremistanDomains where a single observation can dominate the total - wealth, book sales, pandemic spread, social-media reach, war casualties.

Read the original book

This part of the knowledge base is inspired by the book. Go to the Ukrainian edition to explore the concept in depth.

Buy «Чорний лебідь»