Right, but of what use is it if we still rely on our intuitions to come up with a prior probability and a numerical utility assignment?
Just because our brains haven't evolved to deal with a specific circumstance doesn't mean that all of our intuitions would be worthless in that circumstance. Me trying to decide what to invest in doesn't mean that my brain's claim of me currently sitting in a chair inside my home would suddenly become a worthless hallucination. Even if I'm investing, I can still trust the intuition that I'm at my home and sitting in a chair.
If we apply an intuition Y to situation X, then Y might always produce correct results for that X, or it might always produce wrong results for that X, or it might be somewhere in between. Sometimes we take an intuition that we know to be incorrect, and replace it with another decision-making procedure, such the principle of expected utility. If the intuitions which feed into that decision-making procedure are thought to be correct, then that's all that we need to do. Our intuitions may be incapable of producing exact numeric estimates, but they can still provide rough magnitudes.
Which intuitions are correct in which situations? When do we need to replace an intuition with learned rules or decision-making procedures? Well, that's what the heuristics and biases literature tries to find out.
Why wouldn't I just assign any utility to get the desired result? If you can't ground utility in something that is physically measurable, then of what use is it other than giving your beliefs and decisions a veneer of respectability?
What? You don't "assign a utility to get the desired result", you try to figure out what the desired result is. Of course, if you've already made a decision and want to rationalize it, then sure, you can do it by dressing it up in the language expected utility. But that doesn't change the fact that if you want to know whether you should participate, the principle of expected utility is the way to get the best result.
Here the quantities involved even let you make an explicit calculation, if you want to: you know what the prizes are, you know what you have to give up to participate, and you can find out how many people typically participate in such events. Though you can probably get close enough to the right result even without an explicit calculation.
Sometimes we take an intuition that we know to be incorrect, and replace it with another decision-making procedure, such the principle of expected utility. If the intuitions which feed into that decision-making procedure are thought to be correct, then that's all that we need to do.
1) What decision-making procedure do you use to replace intuition with another decision-making procedure?
2) What decision-making procedure is used to come up with numerical utility assignments and what evidence do you have that it is correct by a certain probability?
...Our int
I would like to ask for help on how to use expected utility maximization, in practice, to maximally achieve my goals.
As a real world example I would like to use the post 'Epistle to the New York Less Wrongians' by Eliezer Yudkowsky and his visit to New York.
How did Eliezer Yudkowsky compute that it would maximize his expected utility to visit New York?
It seems that the first thing he would have to do is to figure out what he really wants, his preferences1, right? The next step would be to formalize his preferences by describing it as a utility function and assign a certain number of utils2 to each member of the set, e.g. his own survival. This description would have to be precise enough to figure out what it would mean to maximize his utility function.
Now before he can continue he will first have to compute the expected utility of computing the expected utility of computing the expected utility of computing the expected utility3 ... and also compare it with alternative heuristics4.
He then has to figure out each and every possible action he might take, and study all of their logical implications, to learn about all possible world states he might achieve by those decisions, calculate the utility of each world state and the average utility of each action leading up to those various possible world states5.
To do so he has to figure out the probability of each world state. This further requires him to come up with a prior probability for each case and study all available data. For example, how likely it is to die in a plane crash, how long it would take to be cryonically suspended from where he is in case of a fatality, the crime rate and if aliens might abduct him (he might discount the last example, but then he would first have to figure out the right level of small probabilities that are considered too unlikely to be relevant for judgment and decision making).
I probably miss some technical details and got others wrong. But this shouldn't detract too much from my general request. Could you please explain how Less Wrong style rationality is to be applied practically? I would also be happy if you could point out some worked examples or suggest relevant literature. Thank you.
I also want to note that I am not the only one who doesn't know how to actually apply what is being discussed on Less Wrong in practice. From the comments:
I can't help but agree.
P.S. If you really want to know how I feel about Less Wrong then read the post 'Ontological Therapy' by user:muflax.
1. What are "preferences" and how do you figure out what long-term goals are stable enough under real world influence to allow you to make time-consistent decisions?
2. How is utility grounded and how can it be consistently assigned to reflect your true preferences without having to rely on your intuition, i.e. pull a number out of thin air? Also, will the definition of utility keep changing as we make more observations? And how do you account for that possibility?
3. Where and how do you draw the line?
4. How do you account for model uncertainty?
5. Any finite list of actions maximizes infinitely many different quantities. So, how does utility become well-defined?