Definition and Wald's Bombers
Survivorship bias is a systematic cognitive distortion that occurs when only successful cases or surviving subjects are observable, while failures and dropouts remain invisible. During World War II, statistician Abraham Wald argued that armor should be added to the areas of returning bombers that showed no bullet holes, reasoning that planes hit in those areas never made it back.
Survivorship Bias in Ranking Data
Most world rankings only include countries and individuals for which data exists. Regions with underdeveloped statistical infrastructure and populations unable to participate in surveys are excluded, potentially making results appear more optimistic than reality.
When checking your ranking on MyRank, it is important to consider what dropout biases may exist in the comparison population.
The Trap of Success Rankings
Wealth rankings and entrepreneurial success stories are classic examples of survivorship bias. The countless people who followed the same strategies but failed never appear in rankings, distorting analysis of success factors. "Common traits of the top 1%" may ignore that the bottom 99% shares many of those same traits.
Counteracting Survivorship Bias
To counter survivorship bias, habitually ask "what data am I not seeing?" When viewing ranking results, first check the population definition and exclusion criteria. When learning from success stories, actively seek out cases that failed under similar conditions to achieve more accurate probability assessments.