Coming from a background in scientific instruments, I always find this kind of analysis a bit jarring with its infinite regress involving the rational, self-interested actor at the core.
Of course two instruments will agree if they share the same nature, within the same environment, measuring the same object. You can map onto that a model of priors, likelihood function and observed evidence if you wish. Translated to agreement between two agents, the only thing remaining is an effective model of the relationship of the observer to the observed.
The crucial difference here is that the two “instruments” share the same nature, but they are “measuring” different objects — that is, the hypothetical rationalists do not have access to the same observed evidence about the world. But by virtue of “measuring”, among other things, one another, they are supposed to come into agreement.
Coming from a background in scientific instruments, I always find this kind of analysis a bit jarring with its infinite regress involving the rational, self-interested actor at the core.
Of course two instruments will agree if they share the same nature, within the same environment, measuring the same object. You can map onto that a model of priors, likelihood function and observed evidence if you wish. Translated to agreement between two agents, the only thing remaining is an effective model of the relationship of the observer to the observed.
The crucial difference here is that the two “instruments” share the same nature, but they are “measuring” different objects — that is, the hypothetical rationalists do not have access to the same observed evidence about the world. But by virtue of “measuring”, among other things, one another, they are supposed to come into agreement.