Within about three weeks of a disaster, an official declaration that there can be no more survivors will be wrong.
Berg's third law names a recurring institutional failure: the point at which search is officially abandoned is set by the cost of continuing and by the need to manage expectations, not by the biology of survival. Because the announcement is a resource decision presented as a finding of fact, it is periodically falsified by someone pulled out alive afterwards.
In practice
- A rescue called off on the fourth day is followed on the sixth by a survivor, and no individual decision was unreasonable.
- A project declared unrecoverable by a steering group is quietly finished by two people who were not asked.
- Possible explanations
- The explanation is institutional: the point at which a search is called off is set by the cost of continuing and by the need to manage expectations, not by the biology of survival, and the two need not coincide.
- In its favour
- Survivors have repeatedly been found after official declarations, in earthquakes and mine collapses, which is the pattern the law names.
- Against it
- It is stated as a law from repeated cases rather than a rate, the three-week figure is not derived from data, and the survivors who are found are far more memorable than the searches that correctly concluded.
- Standing
- From Berg's numbered set, first codified on his blog in 2005. Stated as a law on the strength of repeated cases rather than a rate, and the three-week window is not derived from survival data. Survival past several days is rare and documented, so the claim is directionally supported and quantitatively invented.
- Subject
- Risk & Reliability
- Essay
- How much caution, and the jokes about its limits