All of findis's Comments + Replies

findis00

Yep. The most common model that yields a rational agent who will choose to restrict zir own future actions is beta-delta discounting, or time inconsistent preferences. I've had problem sets with such questions, usually involving a student procrastinating on an assignment; I don't think I can copy them, but let me know if you want me to sketch out how such a problem might look.

Actually, maybe the most instrumental-rationality-enhancing topics to cover that have legitimate game theoretic aspects are in behavioral economics. Perhaps you could construct examples where you contrast the behavior of an agent who interprets probabilities in a funny way, as in Prospect Theory, with an agent who obeys the vNM axioms.

findis10

The standard definition of "rationality" in economics is "having complete and transitive preferences", and sometimes "having complete and transitive preferences and adhering to the von Neumann-Morgenstern axioms". Not the way it's used on Less Wrong.

I think the really cool thing about game theory is how far you can go by stating the form of a game and deriving what someone will do, or the possible paths they may take, assuming only that they have rational preferences.

0ThisSpaceAvailable
Making sure that students know what definition is being used is very important. Although to be pedantic, there are assumptions beyond just assuming rational inference, such as recursive metaknowledge (all players know all public knowledge, everyone knows that everyone knows, everyone knows that everyone knows that everyone knows, etc.), that are used in game theory.
findis30

Wouldn't a rational consequentialist estimate the odds that the policy will have unpredictable and harmful consequences, and take this into consideration?

Regardless of how well it works, consequentialism essentially underlies public policy analysis and I'm not sure how one would do it otherwise. (I'm talking about economists calculating deadweight loss triangles and so on, not politicians arguing that "X is wrong!!!")

-2Eugine_Nier
The discussion was about consequentialist heuristics, not hypothetical perfectly rational agents.
findis00

Why is whether your decision actually changes the boxes important to you? [....] If you argue yourself into a decision theory that doesn't serve you well, you've only managed to shoot yourself in the foot.

In the absence of my decision affecting the boxes, taking one box and leaving $1000 on the table still looks like shooting myself in the foot. (Of course if I had the ability to precommit to one-box I would -- so, okay, if Omega ever asks me this I will take one box. But if Omega asked me to make a decision after filling the boxes and before I'd made a precommitment... still two boxes.)

I think I'm going to back out of this discussion until I understand decision theory a bit better.

4Desrtopa
Feel free. You can revisit this conversation any time you feel like it. Discussion threads never really die here, there's no community norm against replying to comments long after they're posted.
findis00

Do you choose to hit me or not?

No, I don't, since you have a time-turner. (To be clear, non-hypothetical-me wouldn't hit non-hypothetical-you either.) I would also one-box if I thought that Omega's predictive power was evidence that it might have a time turner or some other way of affecting the past. I still don't think that's relevant when there's no reverse causality.

Back to Newcomb's problem: Say that brown-haired people almost always one-box, and people with other hair colors almost always two-box. Omega predicts on the basis of hair color: both bo... (read more)

2Desrtopa
If the agent filling the boxes follows a consistent, predictable pattern you're outside of, you can certainly use that information to do this. In Newcomb's Problem though, Omega follows a consistent, predictable pattern you're inside of. It's logically inconsistent for you to two box and find they both contain money, or pick one box and find it's empty. Why is whether your decision actually changes the boxes important to you? If you know that picking one box will result in your receiving a million dollars, and picking two boxes will result in getting a thousand dollars, do you have any concern that overrides making the choice that you expect to make you more money? A decision process of "at all times, do whatever I expect to have the best results" will, at worst, reduce to exactly the same behavior as "at all times, do whatever I think will have a causal relationship with the best results." In some cases, such as Newcomb's problem, it has better results. What do you think the concern with causality actually does for you? We don't always agree here on what decision theories get the best results (as you can see by observing the offshoot of this conversation between Wedrifid and myself,) but what we do generally agree on here is that the quality of decision theories is determined by their results. If you argue yourself into a decision theory that doesn't serve you well, you've only managed to shoot yourself in the foot.
findis-10

you will achieve a net gain of $4950*p(x) over a non-committer (a very small number admittedly given that p(x) is tiny, but for the sake of the thought experiment all that matters is that it's positive.)

Given that someone who makes such a precommitment comes out ahead of someone who doesn't - shouldn't you make such a commitment right now?

Right now, yes, I should precommit to pay the $100 in all such situations, since the expected value is p(x)*$4950.

If Omega just walked up to me and asked for $100, and I had never considered this before, the value of t... (read more)

findis00

The difference between this scenario and the one you posited before, where Ann's mom makes her prediction by reading your philosophy essays, is that she's presumably predicting on the basis of how she would expect you to choose if you were playing Omega.

Ok, but what if Ann's mom is right 99% of the time about how you would choose when playing her?

I agree that one-boxers make more money, with the numbers you used, but I don't think that those are the appropriate expected values to consider. Conditional on the fact that the boxes have already been filled... (read more)

1ArisKatsaris
You are focusing too much on the "already have been filled", as if the particular time of your particular decision is relevant. But if your decision isn't random (and yours isn't), then any individual decision is dependent on the decision algorithm you follow -- and can be calculated in exactly the same manner, regardless of time. Therefore in a sense your decision has been made BEFORE the filling of the boxes, and can affect their contents. You may consider it easier to wrap your head around this if you think of the boxes being filled according to what result the decision theory you currently have would return in the situation, instead of what decision you'll make in the future. That helps keep in mind that causality still travels only one direction, but that a good predictor simply knows the decision you'll make before you make it and can act accordingly.
-2Desrtopa
I would one-box. I gave the relevant numbers on this in my previous comment; one-boxing has an expected value of $990,000,000 to the expected $10,001,000 if you two-box. When you're dealing with a problem involving an effective predictor of your own mental processes (it's not necessary for such a predictor to be perfect for this reasoning to become salient, it just makes the problems simpler,) your expectation of what the predictor will do or already have done will be at least partly dependent on what you intend to do yourself. You know that either the opaque box is filled, or it is not, but the probability you assign to the box being filled depends on whether you intend to open it or not. Let's try a somewhat different scenario. Suppose I have a time machine that allows me to travel back a day in the past. Doing so creates a stable time loop, like the time turners in Harry Potter or HPMoR (on a side note, our current models of relativity suggest that such loops are possible, if very difficult to contrive.) You're angry at me because I've insulted your hypothetical scenario, and are considering hitting me in retaliation. But you happen to know that I retaliate against people who hit me by going back in time and stealing from them, which I always get away with due to having perfect alibis (the police don't believe in my time machine.) You do not know whether I've stolen from you or not, but if I have, it's already happened. You would feel satisfied by hitting me, but it's not worth being stolen from. Do you choose to hit me or not? If the professor is a perfect predictor, then I would deliberately get most of the problems wrong, thereby all but guaranteeing a score of over 100 points. I would have to be very confident that I would get a score below fifty even if I weren't trying to on purpose before trying to get all the questions right would give me a higher expected score than trying to get most of the questions wrong. If the professor posts the list on the boa
findis00

I think it is worth preserving a distinction between the specific kind of signaling Patrick describes and a weaker definition, because "true signaling" explains a specific phenomenon: in equilibrium, there seems to be too much effort expended on something, but everyone is acting in their own best interest. "High-quality" people do something to prove they are high quality, and "low-quality" people imitate this behavior. If education is a signal, people seem to get "too much" education for what their jobs require.

As i... (read more)

1beoShaffer
What Patrick refers to is called costly signaling in evolutionary psychology, and I believe in general.
findis70

Differences in conformity: women may conform a bit more to widespread social views (at least, to views of "their social class") and/or compartimentalize more between what they learn about a specific topic and their general views. This would mean female scientists would be slightly less likely to be atheists in religious countries, female theology students would be slightly less likely to be fanatics in not-that-fanatical societies, etc.

We need to look at differences between men and women conditional on the fact that they've become economists, ... (read more)

findis00

To be properly isomorphic to the Newcomb's problem, the chance of the predictor being wrong should approximate to zero.

If I thought that the chance of my friend's mother being wrong approximated to zero, I would of course choose to one-box. If I expected her to be an imperfect predictor who assumed I would behave as if I were in the real Newcomb's problem with a perfect predictor, then I would choose to two-box.

Hm, I think I still don't understand the one-box perspective, then. Are you saying that if the predictor is wrong with probability p, you would ... (read more)

0Desrtopa
You choose the boxes according to the expected value of each box choice. For a 99% accurate predictor, the expected value of one-boxing is $990,000,000 (you get a billion 99% of the time, and nothing 1% of the time,) while the expected value of two-boxing is $10,001,000 (you get a thousand 99% of the time, and one billion and one thousand 1% of the time.) The difference between this scenario and the one you posited before, where Ann's mom makes her prediction by reading your philosophy essays, is that she's presumably predicting on the basis of how she would expect you to choose if you were playing Omega. If you're playing against an agent who you know will fill the boxes according to how you would choose if you were playing Omega (we'll call it Omega-1,) then you should always two-box (if you would one-box against Omega, both boxes will contain money, so you get the contents of both. If you would two-box against Omega, only one box would contain money, and if you one-box you'll get the empty one.) An imperfect predictor with random error is a different proposition from an imperfect predictor with nonrandom error. Of course, if I were dealing with this dilemma in real life, my choice would be heavily influenced by considerations such as how likely it is that Ann's mom really has billions of dollars to give away.
findis190

I await the eager defenses of belief in belief in the comments, but I wonder if anyone would care to jump ahead of the game and defend belief in belief in belief? Might as well go ahead and get it over with.

My boyfriend was once feeling a bit tired and unmotivated for a few months (probably mild depression), and he also wanted to stop eating dairy for ethical reasons. He felt that his illness was partly mentally generated. He decided that he was allergic to dairy, and that dairy was causing his illness. Then he stopped eating dairy and felt better!

He t... (read more)

findis00

My rule of thumb is that I generally don't buy an X for myself unless I've tried living without it, then borrowed a friend's X and found it helpful. This mainly applies to cooking and hiking instruments. And I try really really hard to not buy yarn (for knitting) without a project in mind.

findis140

Hi, I'm Liz.

I'm a senior at a college in the US, soon to graduate with a double major in physics and economics, and then (hopefully) pursue a PhD in economics. I like computer science and math too. I'm hoping to do research in economic development, but more relevantly to LW, I'm pretty interested in behavioral economics and in econometrics (statistics). Out of the uncommon beliefs I hold, the one that most affects my life is that since I can greatly help others at a small cost to myself, I should; I donate whatever extra money I have to charity, although ... (read more)

3John_Maxwell
Welcome to LW. Also not an expert on Newcomb's Problem, but I'm a one-boxer because I choose to have part of my brain say that I'm a one-boxer, and have that part of my brain influence my behavior if I get in to a Newcomb-like situation. Does that make any sense? Basically, I'm choosing to modify my decision algorithm so I no longer maximize expected value because I think having this other algorithm will get me better results.
0Desrtopa
To be properly isomorphic to the Newcomb's problem, the chance of the predictor being wrong should approximate to zero. If I thought that the chance of my friend's mother being wrong approximated to zero, I would of course choose to one-box. If I expected her to be an imperfect predictor who assumed I would behave as if I were in the real Newcomb's problem with a perfect predictor, then I would choose to two-box. In Newcomb's Problem, if you choose on the basis of which choice is consistent with a higher expected return, then you would choose to one-box. You know that your choice doesn't cause the box to be filled, but given the knowledge that whether the money is in the box or not is contingent on a perfect predictor's assessment of whether or not you were likely to one-box, you should assign different probabilities to the box containing the money depending on whether you one-box or two-box. Since your own mental disposition is evidence of whether the money is in the box or not, you can behave as if the contents were determined by your choice.