Agreeing to Disagree
Two people, 1 and 2, are said to have common knowledge of an event E if both know it, 1 knows that 2 knows it, 2 knows that 1 knows it, 1 knows that 2 knows that 1 knows it, and so on.
Theorem If two people have the same priors, and their posteriors for an event A are common knowledge, then these posteriors are equal.
This work was supported by National Science Foundation Grant SOC74-11446 at the Institute for Mathematical Studies in the Social Sciences, Stanford University.
- Dalkey, N. C. (1972). Studies in the quality of life. Lexington: Lexington Books.Google Scholar
- Grossman, S. J., & Stiglitz, J. E. (1976). Information and competitive price systems. The American Economic Review, 46, 246–253.Google Scholar
- Harsanyi, J. (1967–1968). Games of incomplete information played by Bayesian players, Parts I–III. Management Science, 14, 159–182, 320–334, 486–502.Google Scholar