Polymeron comments on Pascal's Mugging: Tiny Probabilities of Vast Utilities - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (334)
The problem is one of rational behavior, not of bounded-rational hacks.
Are you saying that it's a good thing that the AI uses this rounding system and goes against its values this particular time?
If so, how did you tell that it was a good thing?
Can you mathematically formalize that intuition?
If you cannot do so, there is probably some other conflict between your intuitions and your AI code.
Actually, I think I made a mistake there.
Don't get me wrong, in my suggestion the AI is NOT going against its values nor being irrational, and this was not meant as a hack. Rather I'm claiming that the basic method of doing rationality as described needs revision that accounts for practicality, and if you disagree with that then your next rational move should DEFINITELY be to send me 50$ RIGHT NOW because I TOTALLY have a button that kicks 4^^^^4 puppies if I press it RIGHT HERE.
Having said that, I do think I might have made an error of intuition in there, so let's rethink it. Just because we should rethink what constitutes rational behavior does not mean I got it right.
Suppose I am an omnipotent being and have created a button that does something, once, if pressed. I truthfully tell you that there are several possible outcomes: 1. You receive 10$. This has a chance of 45% chance of happening. 2. You lose 5$. This, too, has a chance of 45% chance of happening. 3. Something else happens.
You should be pretty interested in what this "something else" might be before you press the button, since I've put absolutely no bounds on it. You could win 1000$. Or you could die. The whole world could die. You would wake up in a protein bath outside the Matrix. etc. etc. Some of these things you might be able to prepare for, if you know about them in advance.
If you're rational and you get no further information, you should probably press the button. The overall gain is 5$; as in Pascal's Wager, the infinity of possibilities that stem from the third option cancel each other out.
Now, suppose before I tell you that you get 10 guesses as to what the third thing is. Every time you guess, I tell you the precise probability that this thing is possible. Furthermore, the third option could do at least 12 different things, so no matter what you guessed, you would not be able to tell exactly what the button might do.
So you start guessing. One of your guesses is "3^^^^3 people will die horribly". I rate that one as a 10^-100 chance.
You've reached the end of the guesses and still a full 5% of probability remain - half of the third option's share.
So. Now do we press the button?
My claim was that the you should ignore every outcome smaller than 1% chance in this case, regardless of its utility. This now seems to me like a mistake. In theory, when we add the utility of all known options, it comes out extremely negative. Because the remaining 5% unknowns still have effectively zero chance of happening each, and they STILL cancel each other out.
I think I even know where my mathematical error was: I was assuming that anything less than 1% is a waste of a guess and therefore we should have guessed something else, which quite possibly has a higher chance - this establishes a cutoff for "a calculation that was not worth doing". However in this new example there are at least 12 things the button can do; essentially the number is infinite as far as I know. I should count myself VERY lucky to get 1% or more for anything I guess. In fact I should expect to get an answer of zero or epsilon for pretty much everything. That means that no guess is truly wasted or trivial.
Of course, if we don't press the button the Pascal Muggers will have won...
Back to the drawing board, I guess? :-/
If the injured parties are humans, I should be very skeptical of the assertion because a very small fraction, (1/3^^3)*1/10^(something), of people have the power of life and death over 3^^^3 other people, whereas 1/10^(something smaller) hear the corresponding hoax.
That's the only answer that makes sense because it's the only answer that works on a scale of 3^^^3.
I think.
"If the injured parties are humans, I should be very skeptical of the assertion because a very small fraction, (1/3^^3)*1/10^(something)"
I'm trying to think up several avenues. One is that the higher the claimed utility, the lower the probability (somehow); another tries to use the implications that accepting the claim would have on other probabilities in order to cancel it out.
I'll post a new comment if I manage to come up with anything good.
I know because of anthropics. It is a logical impossibility for more than 1/3^^^3 individuals to have that power. You and I cannot both have power over the same thing, so the total amount of power is bounded, hopefully by the same population count we use to calculate anthropics.
Not in the least convenient possible world. What if someone told you that 3^^^3 copies of you were made before you must make your decision and that their behaviour was highly correlated as applies to UDT? What if the beings who would suffer had no consciousness, but would have moral worth as judged by you(r extrapolated self)? What if there was one being who was able to experience 3^^^3 times as much eudaimonia as everyone else? What if the self-indication assumption is right?
<troll> If you're going to engage in motivated cognition at least consider the least convenient possible world. </troll>
Am I talking to Omega now, or just some random guy? I don't understand what is being discussed. Please elaborate?
Then my expected utility would not be defined. There would be relatively simple worlds with arbitrarily many of them. I honestly don't know what to do.
Then my expected utility would not be defined. There would be relatively simple agents with arbitrarily sensitive utilities.
Then I would certainly live in a world with infinitely many agents (or I would not live in any worlds with any probability), and the SIA would be meaningless.
My cognition is motivated by something else - by the desire to avoid infinities.
1) Sorry, I confused this with another problem; I meant some random guy.
2/3) Isn't how you decision process handles infinities rather important? Is there any corresponding theorem to the Von Neumann–Morgenstern utility theorem but without using either version of axiom 3? I have been meaning to look into this and depending on what I find I may do a top-level post about it. Have you heard of one?
edit: I found Fishburn, 1971, A Study of Lexicographic Expected Utility, Management Science. It's behind a paywall at http://www.jstor.org/pss/2629309. Can anyone find a non-paywall version or email it to me?
4) Yeah, my fourth one doesn't work. I really should have known better.
Sometimes, infinities must be made rigourous rather than eliminated. I feel that, in this case, it's worth a shot.
What worries me about infinities is, I suppose, the infinite Pascal's mugging - whenever there's a single infinite broken symmetry, nothing that happens in any finite world matters to determine the outcome.
This implies that all are thought should be devoted to infinite rather than finite worlds. And if all worlds are infinite, it looks like we need to do some form of SSA dealing with utility again.
This is all very convenient and not very rigorous, I agree. I cannot see a better way, but I agree that we should look. I will use university library powers to read that article and send it to you, but not right now.
I don't see any way to avoid the infinite Pascal's mugging conclusion. I think that it is probably discouraged due to a history of association with bad arguments and the actual way to maximize the chance of infinite benefit will seem more acceptable.
Thank you.
I've been thinking about Pascal's Mugging with regard to decision making and Friendly AI design, and wanted to sum up my current thoughts below.
1a: Assuming you are Pascal Mugged once, it greatly increases the chance of you being Pascal Mugged again.
1b: If the first mugger threatens 3^^^3 people, the next mugger can simply threaten 3^^^^3 people. The mugger after that can simply threaten 3^^^^^3 people.
1c: It seems like you would have to take that into account as well. You could simply say to the mugger, "I'm sorry, but I must keep my Money because the chance of their being a second Mugger who threatens one Knuth up arrow more people then you is sufficiently likely that I have to keep my money to protect those people against that threat, which is much more probable now that you have shown up."
1d: Even if the Pascal Mugger threatens an Infinite number of people with death, a second Pascal Mugger might threaten an Infinite number of people with a slow, painful death. I still have what appears to be a plausible reason to not give the money.
1e: Assume the Pascal Mugger attempts to simply skip that and say that he will threaten me with infinite disutility. The Second Pascallian Mugger could simply threaten me with an infinite disutility of a greater cardinality.
1f: Assume the Pascalian Mugger attempts to threaten me with an Infinite Disutility with the greatest possible infinite Cardinality. A subsequent Pascallian Mugger could simply say "You have made a mathematical error in processing the previous threats, and you are going to make a mathematical error in processing future threats. The amount of any other past or future Pascal's mugger threat is essentially 0 disutility compared to the amount of disutility I am threatening you with, which will be infinitely greater."
I think this gets into the Berry Paradox when considering threats. "A threat infinitely worse then the greatest possible threat statable in one minute." can be stated in less then one minute, so it seems as if it is possible for a Pascal's mugger to make a threat which is infinite and incalculable.
I am still working through the implications of this but I wanted to put down what I had so far to make sure I could avoid errors.