Survivorship Bias

We systematically overestimate our chances of success because failures remain invisible. Only the winners are visible; the losers are forgotten.

• In WWII, engineers studied returning damaged planes and wanted to reinforce the hit areas — statistician Abraham Wald pointed out they should reinforce where the planes were NOT hit, because planes hit there never returned.
• College dropouts like Bill Gates became billionaires — but millions of dropouts who failed are never mentioned.
• Old buildings look beautiful because the ugly ones were torn down long ago. We think ancient architects were brilliant — we just don't see their failures.