The argument I give against assigning precise credences is that itâs arbitrary â literally, you pick one precise credence over many others for no reason. To me, âyou have no reason to do this thingâ is a pretty darn strong argument. :) (ETA: I like the intuition pump in this very short post, if it helps.)
doesnât say why this means we shouldnât/âcanât pick credences according to our best effort.
Why does âour best effortâ need to be precise? Can you say more what exactly you mean? (If the intuition is that more precision = more information, I address that in the post.)
It also doesnât say why, if we can measure short term value, we shouldnât use that as a justification for our decisionmaking process and assume EV from events that we donât think we can assess is 0.
I address this in the unawareness sequence. I recommend reading the table in my summary post â the row with âEven if our impact is dominated by consequences weâre unaware of...â â for the high-level idea, and the links therein for details.
especially when weâre not given an alternative
Isnât this privileging the hypothesis? My claim is that we donât have a positive argument in favor of doing what the precise EV approach recommends (or fuzzier âbest guessesâ, either). If our best defense of that approach is âwhat else is there?â, that seems rather damning.
literally, you pick one precise credence over many others for no reason
At some foundational level, a credence has no deeper reason than âsome neurons fired that wayâ. But you donât need to restrict yourself to concerns about the whole future lightcone to run into this problemâat the foundational level this is true of every statement.
There are various ways one might respond to this challenge, but if we donât view it as insurmountable elsewhere, I donât see why we should do so with credences (which are of course usually non-foundational statements). And if we do, it undermines e.g. any argument about unawareness.
Why does âour best effortâ need to be precise?
It only needs to be as precise as is necessary for decision-making. I will probably never need to forecast rain to 8 decimal places. But if youâre saying forecasting rain as âless than .5â is ok, but that forecasting 0.1234567% chance of rain if the extra precision was actually decision-relevant, would be un-ok/âimpossible/âqualitatively different, then I disagree.
(from link) It doesnât follow from âwe donât know the net direction of the consequences weâre unaware ofâ that we should regard the positives and negatives as precisely symmetric. One reason symmetry is implausible: If we become aware of a new possible consequence, this should update our beliefs about the others weâre unaware of, breaking the symmetry.
If you âbecome awareâ of something, youâve gained information and should update your priors accordingly. That doesnât move me away from being happy to treat genuine unknowns as EV-0. Your counterpoint seems to be that in some cases that feel sort-of- equal (and about which, in the cases you describe we actually have a lot of information), we might be inclined to give equal credence. But it seems to me correct to say âif you have meaningful knowledge of two possible outcomes, and the weight you assign to them is decision-relevant, giving them equal credence is a mistakeâ, which fixes this purported problem without radically undermining our epistemology.
My claim is that we donât have a positive argument in favor of doing what the precise EV approach recommends
The precise EV approach is well evidenced in short-term decision-making, so the positive argument is that there isnât any principled difference between short and long-term decision-making
(Due to time constraints I expect I can only give brief replies/âclarifications, going forward. I hope a full read of the sequence will suffice, though I realize itâs quite long, sorry!)
But you donât need to restrict yourself to concerns about the whole future lightcone to run into this problemâat the foundational level this is true of every statement. ⌠I donât see why we should do so with credences (which are of course usually non-foundational statements)
(See my last para for the âfuture lightconeâ thing.)
I donât understand your Munchausen trilemma argument yet. You say credences are âof course usually non-foundationalâ. Agreed! Thatâs exactly why I think our choices of credences require deeper justification. (Whereas foundational things, like Huemerâs âseemingsâ, donât.[1])
forecasting 0.1234567% chance of rain if the extra precision was actually decision-relevant
The extra precision might be âdecision-relevantâ in the sense that: if you were justified in a credence of 0.1234567% + 0.0000001%, you should choose A, and if you were justified in a credence of 0.1234567% â 0.0000001%, you should choose B. But the whole question is why weâd be justified in the former vs. the latter, epistemically. (âI need to make a choiceâ isnât a justification for any particular option you choose.)
Your counterpoint seems to be that in some cases that feel sort-of- equal (and about which, in the cases you describe we actually have a lot of information), we might be inclined to give equal credence.
Thatâs not what Iâm saying, sorry â Iâm denying we should give equal credence. Please see my reply to a similar comment here, and section 3.2.1 and 4.1.1 of the sequence (you might need to CTRL+F some terms defined earlier in the sequence). If itâs still unclear, Iâm happy to try to explain further if you could point to particular passages that need clarification.
The precise EV approach is well evidenced in short-term decision-making
I donât know what exactly this means. If you mean âwe seem to be justified in using precise EVs in short term decision makingâ:
I think our beliefs shouldnât be precise in basically any real-world case, not just beliefs about the far future. (Sec 2.2)
So I think whatâs going on is simply that short term decisions arenât sensitive to the imprecision in the beliefs weâre actually justified in having. The principled difference from the far future case is that in the latter, our decisions are sensitive to the imprecision.
Hi Arepo, thanks for sharing your cruxes here.
The argument I give against assigning precise credences is that itâs arbitrary â literally, you pick one precise credence over many others for no reason. To me, âyou have no reason to do this thingâ is a pretty darn strong argument. :) (ETA: I like the intuition pump in this very short post, if it helps.)
Why does âour best effortâ need to be precise? Can you say more what exactly you mean? (If the intuition is that more precision = more information, I address that in the post.)
I address this in the unawareness sequence. I recommend reading the table in my summary post â the row with âEven if our impact is dominated by consequences weâre unaware of...â â for the high-level idea, and the links therein for details.
Isnât this privileging the hypothesis? My claim is that we donât have a positive argument in favor of doing what the precise EV approach recommends (or fuzzier âbest guessesâ, either). If our best defense of that approach is âwhat else is there?â, that seems rather damning.
At some foundational level, a credence has no deeper reason than âsome neurons fired that wayâ. But you donât need to restrict yourself to concerns about the whole future lightcone to run into this problemâat the foundational level this is true of every statement.
There are various ways one might respond to this challenge, but if we donât view it as insurmountable elsewhere, I donât see why we should do so with credences (which are of course usually non-foundational statements). And if we do, it undermines e.g. any argument about unawareness.
It only needs to be as precise as is necessary for decision-making. I will probably never need to forecast rain to 8 decimal places. But if youâre saying forecasting rain as âless than .5â is ok, but that forecasting 0.1234567% chance of rain if the extra precision was actually decision-relevant, would be un-ok/âimpossible/âqualitatively different, then I disagree.
If you âbecome awareâ of something, youâve gained information and should update your priors accordingly. That doesnât move me away from being happy to treat genuine unknowns as EV-0. Your counterpoint seems to be that in some cases that feel sort-of- equal (and about which, in the cases you describe we actually have a lot of information), we might be inclined to give equal credence. But it seems to me correct to say âif you have meaningful knowledge of two possible outcomes, and the weight you assign to them is decision-relevant, giving them equal credence is a mistakeâ, which fixes this purported problem without radically undermining our epistemology.
The precise EV approach is well evidenced in short-term decision-making, so the positive argument is that there isnât any principled difference between short and long-term decision-making
(Due to time constraints I expect I can only give brief replies/âclarifications, going forward. I hope a full read of the sequence will suffice, though I realize itâs quite long, sorry!)
(See my last para for the âfuture lightconeâ thing.)
I donât understand your Munchausen trilemma argument yet. You say credences are âof course usually non-foundationalâ. Agreed! Thatâs exactly why I think our choices of credences require deeper justification. (Whereas foundational things, like Huemerâs âseemingsâ, donât.[1])
The extra precision might be âdecision-relevantâ in the sense that: if you were justified in a credence of 0.1234567% + 0.0000001%, you should choose A, and if you were justified in a credence of 0.1234567% â 0.0000001%, you should choose B. But the whole question is why weâd be justified in the former vs. the latter, epistemically. (âI need to make a choiceâ isnât a justification for any particular option you choose.)
Thatâs not what Iâm saying, sorry â Iâm denying we should give equal credence. Please see my reply to a similar comment here, and section 3.2.1 and 4.1.1 of the sequence (you might need to CTRL+F some terms defined earlier in the sequence). If itâs still unclear, Iâm happy to try to explain further if you could point to particular passages that need clarification.
I donât know what exactly this means. If you mean âwe seem to be justified in using precise EVs in short term decision makingâ:
I think our beliefs shouldnât be precise in basically any real-world case, not just beliefs about the far future. (Sec 2.2)
So I think whatâs going on is simply that short term decisions arenât sensitive to the imprecision in the beliefs weâre actually justified in having. The principled difference from the far future case is that in the latter, our decisions are sensitive to the imprecision.
That is, they donât require deeper justification prima facie. Theyâre still defeasible.