Aumann's agreement theorem, roughly speaking, says that two agents acting rationally (in a certain precise sense) and with common knowledge of each other's beliefs cannot agree to disagree. More specifically, if two people are genuine Bayesians, share common priors, and have common knowledge of each other's current probability assignments, then they must have equal probability assignments.

Related tags and wikis: Disagreement, Modesty, Modesty argument, Aumann agreement, The Aumann Game

Highlighted Posts

The Modesty Argument
Agreeing to Agree by Hal Finney
The Coin Guessing Game by Hal Finney
The Proper Use of Humility
Meme Lineages and Expert Consensus by Carl Shulman (OB)
Probability Space & Aumann Agreement by Wei Dai
Bayesian Judo

External Links

A write-up of the proof of Aumann's agreement theorem (pdf) by Tyrrell McAllister

See also

References

(PDF)
(PDF, Talk video)

Aumann's Agreement Theorem