Bostrom’s proposal fails even harder than “naive” SSA: it refuses to give a definite answer. He says selecting a reference class may be a “subjective” problem, like selecting a Bayesian prior. Moreover, he says that giving the “intuitively right” answer to problems like mine is one of the desiderata for a good reference class, not a consequence of his approach.
He does not solve the problem of defining the reference class. He doesn’t refuse to give a definite answer. He just doesn’t claim to have given one yet. As you say, he leaves open the possibility that choosing the reference class is like choosing a Bayesian prior, but he only offers this as a possibility. Even while he allows for this possibility, he seems to expect that more can be said “objectively” about what the reference class must be than what he has figured out so far.
So, it’s a work in progress. If it fails, it certainly isn’t because it gives the wrong answer on the coin problem that you posed.
To me it looks abandoned, not in progress. And it doesn’t give any definite answer. And it’s not clear to me whether it can be patched to give the correct answer and still be called “SSA” (i.e. still support some version of the Doomsday argument). For example, your proposed patch (using indistinguishable observers as the reference class) gives the same results as SIA and doesn’t support the DA.
Anyway. We have a better way to think about anthropic problems now: UDT! It gives the right answer in my problem, and makes the DA go away, and solves a whole host of other issues. So I don’t understand why anyone should think about SSA or Bostrom’s approach anymore. If you think they’re still useful, please explain.
Anyway. We have a better way to think about anthropic problems now: UDT! It gives the right answer in my problem, and makes the DA go away, and solves a whole host of other issues. So I don’t understand why anyone should think about SSA or Bostrom’s approach anymore. If you think they’re still useful, please explain.
When it comes to deciding how to act, I agree that the UDT approach to anthropic puzzles is the best I know. Thinking about anthropics in the traditional way, whether via SSA, SIA, or any of the other approaches, only makes sense if you want to isolate a canonical epistemic probability factor in the expected-utility calculation.
He does not solve the problem of defining the reference class. He doesn’t refuse to give a definite answer. He just doesn’t claim to have given one yet. As you say, he leaves open the possibility that choosing the reference class is like choosing a Bayesian prior, but he only offers this as a possibility. Even while he allows for this possibility, he seems to expect that more can be said “objectively” about what the reference class must be than what he has figured out so far.
To me it looks abandoned, not in progress. And it doesn’t give any definite answer. And it’s not clear to me whether it can be patched to give the correct answer and still be called “SSA” (i.e. still support some version of the Doomsday argument). For example, your proposed patch (using indistinguishable observers as the reference class) gives the same results as SIA and doesn’t support the DA.
Anyway. We have a better way to think about anthropic problems now: UDT! It gives the right answer in my problem, and makes the DA go away, and solves a whole host of other issues. So I don’t understand why anyone should think about SSA or Bostrom’s approach anymore. If you think they’re still useful, please explain.
When it comes to deciding how to act, I agree that the UDT approach to anthropic puzzles is the best I know. Thinking about anthropics in the traditional way, whether via SSA, SIA, or any of the other approaches, only makes sense if you want to isolate a canonical epistemic probability factor in the expected-utility calculation.
In the context of the Doomsday Argument, or Great Filter arguments, etc., UDT is typically equivalent to SIA.