Exactly how to cash out objective probabilities is a tricky problem which is the subject of a substantial literature. We didn’t want to tie our definition to any particular version, believing that it’s better to parcel off that problem. But my personal view is that roughly speaking you can get an objective probability by taking something like an average of subjective probabilities of many hypothetical observers.
Sorry, still not making any sense to me. “Taking something like an average of subjective probabilities of many hypothetical observers” looks precisely like GIGO and I don’t understand how do you get something objective out of subjective perceptions of hypotheticals(!).
If you don’t think the concept of “objective probability” is salvageable I agree that you wouldn’t want to use it for defining other things.
I don’t want to go into detail of my personal account of objective probability here, not least because I haven’t spent enough time working it out to be happy it works! The short answer to your question is you need to define an objective measure over possible observers. For the purposes of defining existential risk, you might be better to stop worrying about the word “objective” and just imagine I’m talking about the subjective probabilities assigned by an external observer who is well-informed but not perfectly informed.
Exactly how to cash out objective probabilities is a tricky problem which is the subject of a substantial literature. We didn’t want to tie our definition to any particular version, believing that it’s better to parcel off that problem. But my personal view is that roughly speaking you can get an objective probability by taking something like an average of subjective probabilities of many hypothetical observers.
Sorry, still not making any sense to me. “Taking something like an average of subjective probabilities of many hypothetical observers” looks precisely like GIGO and I don’t understand how do you get something objective out of subjective perceptions of hypotheticals(!).
If you don’t think the concept of “objective probability” is salvageable I agree that you wouldn’t want to use it for defining other things.
I don’t want to go into detail of my personal account of objective probability here, not least because I haven’t spent enough time working it out to be happy it works! The short answer to your question is you need to define an objective measure over possible observers. For the purposes of defining existential risk, you might be better to stop worrying about the word “objective” and just imagine I’m talking about the subjective probabilities assigned by an external observer who is well-informed but not perfectly informed.