Pick a Number

Economist Rob Hanson quoted Tyler Cowen from George Mason University:

We often like to ask lunch visitors what is their most absurd view (in the eyes of others). Alas I have so many choices. On BloggingHeads, Tyler Cowen answers this for Will Wilkinson:

Tyler: My most absurd belief, perhaps, is the extent to which I think people should be truly uncertain about almost all of their beliefs. And it doesn’t sound absurd when you say it but I don’t on the other hand know anyone who agrees with it. … Take whatever your political beliefs happen to be. Obviously the view you hold you think is most likely to be true, but I think you should give that something like 60-40, whereas in reality most people will give it 95 to 5 or 99 to 1 in terms of probability that it is correct. Or if you ask people what is the chance this view of yours is wrong, very few people are willing to assign it any number at all. Or if you ask people who believe in God or are atheists, what’s the chance you’re wrong – I’ve asked atheists what’s the chance you’re wrong and they’ll say something like a trillion to one, and that to me is absurd, that even if you think all of the strongest arguments for atheism are correct, your estimate that atheism is in fact the correct point of view shouldn’t be that high, maybe you know 90-10 or 95 to 5, at most. So that maybe is my most absurd view. Most things are much more up for grabs than we like to say they are.

Will: I agree with you that things are more up for grabs than people think they are, but I have real problems with the idea that it’s either possible or desirable that people assign probabilities to all of their beliefs. I think it’s a weird violation of the actual computational constraints of the human mind, that we just don’t.

Tyler: Here, you are more of a philosopher than I am, and I’m more a Bayesian. I’m sure it’s possible. Now I’m not saying it’s desirable, I’m just saying I want people to do it in a lot of instances, maybe just for my aesthetic pleasure. I want to pin people down and get a sense for how sure they are, and interpret these probabilities as betting odds, if you want. Let’s say there’s a lot of dying starving children in India or sub-Saharan Africa, and you are offered to bet, and you know that the money won on these bets will go to feed these children and save their lives, and you have to name what odds you are going to bet at. And you can name a number. You want to name the best number you can because you want to save the lives of these children, so I’m not going to allow any evasion here. I don’t see why there is not always some pick of a number that’s better than a lot of other picks. You are not going to get it right so computationally of course it’s hopeless. But look, you’ve got to give it your best guess. (emphasis added)

As you might guess from The Design Matrix, I happen to agree with Tyler Cowen. In fact, when he advocates that people “pick a number” and “give it your best guess” such that we can get a sense of how sure people are about their beliefs, he is advocating for intellectual honesty. The Design Matrix likewise advocates for this, but also outlines a systematic approach to implement such an approach to reality. That is one of the aspects of the book that make it completely unique. You can watch the exchange here.

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12 responses to “Pick a Number

  1. One of the most interesting moments of Expelled for me was when Ben Stein interacted with Dawkins about the odds of his atheism being true, and asked him to put a number on it. The whole exchange was telling.

  2. Hi Nulla,

    I don’t remember that exchange. What was Dawkins’ reply?

  3. How about this for a test: Would you be willing to be tortured and executed instead of giving up the belief?

  4. Bilbo,

    I think you can find it on Youtube somewhere, but I couldn’t find it for you just now.

    It went back and forth. Dawkins would say that God’s existence was very unlikely. So Stein asked, alright, what percent of likelihood? Dawkins said, well, he couldn’t put a number on it. Stein’s pressing him, wondering how you can say ‘very unlikely’ but you can’t place a number. Dawkins ends up saying 99 or 98% unlikely, Stein asks, alright – why that unlikely? Why not 97%? Why not less? Dawkins replies well, I didn’t want to put a number on it, I can’t explain it that way. It’s just unlikely! Etc.

    Obviously I’m paraphrasing here, so if you can watch it for yourself, you’d be better off. It plays into Mike’s point here, though I think it may also go beyond it in some ways.

  5. You guys might be interested in this account, as it is similar:

    This morning, I had an interesting conversation with Christopher Hitchens, who’s in town plugging his memoir. He professed to be a man of few beliefs, political or otherwise: “my only commitment is to a group of skeptics who are not sure of anything,” he said. But when I asked him what he wasn’t sure about, he started talking about galaxy formation, of all things. He said that “my greatest delight is being proved right in my own lifetime”, and said that he couldn’t think of the last time that he was wrong about anything. In other words, he’s highly skeptical of others, but utterly incapable of interrogating his own opinions with the same kind of approach.

    I like that last sentence.

    http://blogs.reuters.com/felix-salmon/2010/06/07/helen-thomas-christopher-hitchens-and-being-wrong/

  6. Mr. Dawkins’ reply should have been:

    “That is a silly question, Mr. Stein. But there is a 100% chance that you will be publicly humiliated by trying to trick qualified scientists by misrepresenting yourself about the nature of the interviews, and then editing the questions and replies in false and biased ways for your “film”. You are a silly person, and not qualified to ask any serious person any serious question. Now please return to your cancelled game show.”

  7. Well, technically there’s nothing hypocritical about his statement. If he is honestly and predominantly skeptical, he’s unwilling to draw many or any firm conclusions, and therefore unable to be proved wrong.

    To say that most others are wrong is provable by showing first that people predominantly are not skeptical of their knowledge, and two that different people hold many different contradictory beliefs… neither of which is very controversial.

    As a disclaimer I have no clue whether or not Hitchens is very opinionated, and hence just a half-assed skeptic, or whether he honestly hedges everything he says. Probably he’s a hypocrite! But the outlook presented is reasonable taken on its face.

  8. Interestingly enough, I believe in God and go to church, at least somewhat regularly, yet I would probably only assign a 5% or less probably of there actually being a god. However, that 5% or less seems to be pretty important as it would determine my fate for all time.

  9. White men are less likely to consider this than women, I’ve found.

  10. So what is the Design Matrix?

  11. Franken,

    As you might know, there is a lot of heat surrounding the issue of “Intelligent Design.” The Design Matrix is a method for assessing claims as to whether or not something was designed. That is, it is not some “design detection” method, but more of a method in the spirit of what Tyler Cowen suggests up above. The idea is that there are four criteria that can go either way (depending on the data) – Analogy (with known design); Discontinuity; Rationality; and Foresight. Any system that is proposed as designed or non-designed is assessed with these four criteria using a number scale ranging from -5 to 5. The individual criterion scores are then summed and averaged to give an overall assessment.

  12. As I getting a prescription filled for some Chinese herbal medicine for my wife at her request, I was thinking about this. If the herbalist asked, I was going to tell her,

    –I am skeptical about the efficacy of the herbs. Say, 55% in favor of their efficacy.
    –But then what about Western medicine? –Probably 90% effective [I’m so credulous!].
    –Is your wife really human?
    –I’m 98% sure.
    –Are you?
    –99% sure.

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