I think you're focusing too much on the label "rational", and not enough on the actual effect of beliefs.

I'll admit I'm closer to logical positivism than is Eliezer, but even if you make the argument (which you haven't) that the model of the universe is simpler (in the Kolmogorov complexity sense) by believing Adam killed Able, it's still not important. Unless you're making predictions and taking actions based on a belief (or on beliefs influenced by that belief), it's neither rational nor irrational, it's irrelevant.

Now, a somewhat more complicated example, where Eve has to judge Cain's likelihood of murdering her, and thinks the circumstances of the locked room in the past are relevant to her future, there are definite predictions she should be making. Her confidence in Adam's innocence implies Cain's guilt, and she should be concerned.

It's still the case that she cannot possibly have enough evidence for her confidence to be 1.00.

This belief pays no rent. It's unfalsifiable precisely because it's irrelevant - there is no prediction that Eve can make which would give different outcomes based on Adam's past behavior. The belief just doesn't matter.

Separately, if she assigns 0.0 probability to anything, she's probably not actually as rational as she claims.

Can believing an unfalsifyable believe be rational?

Sure, see http://lesswrong.com/lw/ss/no_logical_positivist_i/

You need at least 10 karma points to vote (you currently have 2 points, according to your profile). Once you have 10 points you should be able to see the voting buttons. Incidentally, after a troll downvoted me from 12 to 4, I lost the ability to vote, and now I can no longer see the buttons.

Hi, I have silly question. How do I vote? It seems obvious but I cannot see any upvote or downvote button anywhere in this page. I have tried:

1. looking at the top of the comment. Next to OP/TS is date, and then time, and then the points. At the far right is the 'minimize'
2. looking at the bottom of the comment. I see Parent, Edit, Permalink, get notification
3. The FAQ says: >you can vote submissions and comments up or down just like you can on Reddit but I cannot find the vote button anywhere near comments or post.

What do you actually want to do with your life? There are careers like politics where personal connection that are gathered during university years are very important.

There are other careers such as starting a startup where personal connections with high status people might not be central and a lot of the YC founders don't have them.

Either there's some sort of self-selection, or do graduates from there have better prospects than graduates of 'University of X, YZ'?

Why "either or"?

I bought a $1400 mattress in my quest for sleep, over the Internet hence much cheaper than the mattress I tried in the store, but non-returnable. When the new mattress didn’t seem to work too well once I actually tried sleeping nights on it, this was making me reluctant to spend even more money trying another mattress. I reminded myself that the $1400 was a sunk cost rather than a future consequence, and didn’t change the importance and scope of future better sleep at stake (occurring once per day and a large effect size each day).

from http://rationality.org/checklist/

Is it rational for someone to choose to NOT buy another mattress, not because of the sunk cost, but in order to "punish" oneself (stick and carrot style) to change their behavior and not buy non-returnable, expensive things, ever again? (or to be more careful when buying expensive things)

I've established a habit of putting my money where my mouth is to encourage myself to make more firm predictions. When I am talking with someone and we disagree, I ask if they want to bet a dollar on it. For example, I say, "Roger Ebert directed Beyond the Valley of the Dolls". My wife says, "No, he wrote it.". Then I offer to bet. We look up the answer, and I give her a dollar.

This is a good habit for many reasons.

1. It is fun to bet. Fun to win. And (kinda) fun to lose.
2. It forces people to evaluate honestly. The same people that say "I'm sure..." will back off their point when asked to bet a dollar on the outcome.
3. It forces people to negotiate to concrete terms. For example, I told a friend that a 747 burns 30,000 lbs of fuel an hour. He said no way. We finally settled on the bet "Ben thinks that a fully loaded 747 will burn more than 10,000 lbs of fuel per hour under standard cruising conditions". (I won that bet, it burns ~25,000 lbs of fuel/hour under these conditions).
4. A dollar feels more important than it actually is, so people treat the bets seriously even though they are not very serious. For this reason, I think it is important to actually exchange a dollar bill at the end, rather than treating it as just an abstract dollar.

I've learned a lot from this habit.

1. I'm right more often than not (~75%). But I'm wrong a lot too (~25%). This is more wrong than I feel. I feel 95% confident. I shouldn't be so confident.
2. The person proposing the bet is usually right. My wife has gotten in the habit too. If I propose we bet, I'm usually right. If she proposes we bet I've learned to usually back down.
3. People frequently overstate their confidence. I mentioned this above, but it bears repeating. Some people regularly will use phrases like "I am sure" or say something emphatically. People are calibrated to express their beliefs differently. But when you ask them to bet a dollar you get a more consistent calibration. People that are over-confident often back away from their positions. Really interesting considering that its only a dollar on the line.
4. Over time people learn to calibrate better. At first my wife would agree to nearly every bet I proposed. Now she usually doesn't want to. When she agrees to a bet now, I get worried.

To the best of my knowledge, human brain is a simulation machine. It unconsciously making prediction about what sensory input it should expect. This include the higher level input, like language and even concepts. This is the basic mechanism underlying surprise and similar emotion. Moreover, it only makes simulation on the things it cares about and filter the rest.

Given this, I would think that most of your prediction is obsolete, because we are doing this unconsciously. Example:

1. You predict you will finish the task one week early. But you are ended up finishing one day early. You are not surprised. But if you ended up finishing one day late, then you would be surprised. When people are surprised by the same trigger often enough, most normal people I presume, will update their believe. I know this is related to planning fallacy, but I think my arguments still hold water.

2. You post a post on Facebook. You didn't make any conscious prediction on the reaction of the audience. You got one million likes. I bet you will be surprised and scratching your mind about why and how you could get such reaction.

Otherwise, I still see some value in what you are doing, but not because of prediction per se, but because you it effectively mitigate bias. For example. "Predict how well you understand someone's position by trying to paraphrase it back to him." It addresses illusion of transparency. But I think there is not much more value in making prediction rather than simply making a habit to paraphrase more often than otherwise without making prediction.

Making conscious prediction, on top of the unconscious one, is cognitively costly. I do think it might improve one's calibration and accuracy and is superior to the improvement made by the surprise mechanism alone. However, the question is, is the calibration and accuracy improvement worth the extra cognitive cost?