Well, I think the whole “reference class” thing is a mistake. By using FNC, one can see that all non-fantastical problems of everyday life that might appear to involve selection effects for which a “reference class” is needed can in fact be solved correctly using standard probability theory, if one doesn’t ignore any evidence. So it’s only the fantastical problems where they might appear useful. But given the fatal flaw that the exact reference class matters, but there is no basis for chosing a particular reference class, the whole concept is of no use for fantastical problems either.
“But given the fatal flaw that the exact reference class matters, but there is no basis for chosing a particular reference class, the whole concept is of no use for fantastical problems either”—well, I plan to write up a post on this soon, but I don’t think that the reference class is as complex as people think for most cases. If you’re deciding whether to take action A, but you need to calculate the probability accounting for anthropic effects, you just consider the population who can take action A.
Well, I guess I’ll have to wait for the details, but off-hand it doesn’t seem that this will work. If action A is “have another child”, and the issue is that you don’t want to do that if the child is going to die if the Earth is destroyed soon in a cataclysm, then the action A is one that can be taken by a wide variety of organisms past and present going back hundreds of millions of years. But many of these you would probably not regard as having an appropriate level of sentience, and some of them that you might regard as sentient seem so different from humans that including them in the reference class seems bizarre. Any sort of line drawn will necessarily be vague, leading to vagueness in probabilities, perhaps by factors of ten or more.
FNC = Full Non-indexical Conditioning, the method I advocate in my paper.
Well, I think the whole “reference class” thing is a mistake. By using FNC, one can see that all non-fantastical problems of everyday life that might appear to involve selection effects for which a “reference class” is needed can in fact be solved correctly using standard probability theory, if one doesn’t ignore any evidence. So it’s only the fantastical problems where they might appear useful. But given the fatal flaw that the exact reference class matters, but there is no basis for chosing a particular reference class, the whole concept is of no use for fantastical problems either.
FNC?
“But given the fatal flaw that the exact reference class matters, but there is no basis for chosing a particular reference class, the whole concept is of no use for fantastical problems either”—well, I plan to write up a post on this soon, but I don’t think that the reference class is as complex as people think for most cases. If you’re deciding whether to take action A, but you need to calculate the probability accounting for anthropic effects, you just consider the population who can take action A.
Well, I guess I’ll have to wait for the details, but off-hand it doesn’t seem that this will work. If action A is “have another child”, and the issue is that you don’t want to do that if the child is going to die if the Earth is destroyed soon in a cataclysm, then the action A is one that can be taken by a wide variety of organisms past and present going back hundreds of millions of years. But many of these you would probably not regard as having an appropriate level of sentience, and some of them that you might regard as sentient seem so different from humans that including them in the reference class seems bizarre. Any sort of line drawn will necessarily be vague, leading to vagueness in probabilities, perhaps by factors of ten or more.
FNC = Full Non-indexical Conditioning, the method I advocate in my paper.