Sorry, I don’t understand the argument yet. Why is it clear that I should bet on odds P, e.g., if P is the distribution that the CCT says I should be represented by?
Because you couldn’t be represented as being an EV-maximizer with beliefs P if you were betting using some odds other than P. Because that would lead to lower expected value. (Assuming that pay-offs are going to be proportional to some proper scoring rule.)
“It’s only permissible to bet at odds that are inside your representor” is only true if the representor is convex. If my credence in some proposition X is, say, P(X) = (0.2, 0.49) U (0.51, 0.7), IIUC it’s permissible to bet at 0.5. I guess the claim that’s true is “It’s only permissible to bet at odds in the convex hull of your representor”.
But I’m not aware of an argument that representors should be convex in general.
If there is such an argument, my guess is that the way things would work is: We start with the non-convex set of distributions that seem no less reasonable than each other, and then add in whichever other distributions are needed to make it convex. But there would be no particular reason we’d need to interpret these other distributions as “reasonable” precise beliefs, relative to the distributions in the non-convex set we started with.
And, the kind of precise distribution P that would rationalize e.g. working on shrimp welfare seems to be the analogue of “betting at 0.5” in my example above. That is:
Our actual “set of distributions that seem no less reasonable than each other” would include some distributions that imply large positive long-term EV from working on shrimp welfare, and some that imply large negative long-term EV.
Whereas the distributions like P that imply vanishingly small long-term EV — given any evidence too weak to resolve our cluelessness w.r.t. long-term welfare — would lie in the convex hull. So betting at odds P would be permissible, and yet this wouldn’t imply that P is “reasonable” as precise beliefs.
Sorry, I don’t understand the argument yet. Why is it clear that I should bet on odds P, e.g., if P is the distribution that the CCT says I should be represented by?
Because you couldn’t be represented as being an EV-maximizer with beliefs P if you were betting using some odds other than P. Because that would lead to lower expected value. (Assuming that pay-offs are going to be proportional to some proper scoring rule.)
Oops, right. I think what’s going on is:
“It’s only permissible to bet at odds that are inside your representor” is only true if the representor is convex. If my credence in some proposition X is, say, P(X) = (0.2, 0.49) U (0.51, 0.7), IIUC it’s permissible to bet at 0.5. I guess the claim that’s true is “It’s only permissible to bet at odds in the convex hull of your representor”.
But I’m not aware of an argument that representors should be convex in general.
If there is such an argument, my guess is that the way things would work is: We start with the non-convex set of distributions that seem no less reasonable than each other, and then add in whichever other distributions are needed to make it convex. But there would be no particular reason we’d need to interpret these other distributions as “reasonable” precise beliefs, relative to the distributions in the non-convex set we started with.
And, the kind of precise distribution P that would rationalize e.g. working on shrimp welfare seems to be the analogue of “betting at 0.5” in my example above. That is:
Our actual “set of distributions that seem no less reasonable than each other” would include some distributions that imply large positive long-term EV from working on shrimp welfare, and some that imply large negative long-term EV.
Whereas the distributions like P that imply vanishingly small long-term EV — given any evidence too weak to resolve our cluelessness w.r.t. long-term welfare — would lie in the convex hull. So betting at odds P would be permissible, and yet this wouldn’t imply that P is “reasonable” as precise beliefs.