This reads like a glorification of quantitative differences into a qualitative difference. Why reify this guide/portfolio distinction?
But simply knowing what an orthodox Chicago School economist thinks about some big question would move me very little.
And why is that?
Is that because they are literally as wrong as they are right, that they are competitive only with a random number generator/max-ent predictor? If they are, then that’s a very peculiar sort of insight they are offering; why do you think you are free of the crippling biases that apparently reduce their otherwise insightful analyses to random noise?
Is it because they are only somewhat more right than wrong, but they do beat random guesses? Then knowing their opinion should move your decision somewhat. (Do they not move your decision at all? But we specified they were better than randomness, and so ignoring their opinion is throwing away some amount of information.) But then, they are also somewhat equivalent to your guide—but only somewhat.
Is it because they are only somewhat more right than wrong, but they do beat random guesses?
is not right. OP might ignore them because his knowledge screens all the information in their opinions. For example, that might be true if he had studied relevant topics and was already an expert in Industrial Organization.
I think the OP’s point would be better said as something like “you should only update your probabilities when a person’s opinion gives additional information rather than when they are an expert.”
I take your point to be that I have taken something that is really a matter of degree “how much weight should I give to the opinion of this or that person?” and turned it into something dichotomous “is this person a good guide for me or not?” Here is my response.
Let’s start by imagining that you can only hear the final opinions of the different advisers, and cannot discuss with them their arguments or evidence relating to the different elements of the question. In that case, the final opinion of anyone who has a valuable insight into any element of the question ought, all else equal, to move the needle for you at least a little bit. But it may be only a very little bit, and it can perfectly well be zero. In the Chicago School example, there are categories of firm conduct that Chicago people think should basically always be permitted, but that people like me think should sometimes be permitted and sometimes not. In those cases, merely knowing the final opinion of a Chicago person about a particular variety of conduct helps me not at all. Another way to get from “X’s opinion should move you a very little bit” to “X’s opinion should move you not at all” by throwing in a small fixed cost of the consultation.
But regardless of whether the adviser’s final opinion moves you not at all or a little bit, the point is that there can still be a lot of value in hearing their arguments/evidence on particular points. If there are things that firms do that Chicago people think should always be permitted, but that people like me think should sometimes be permitted and sometimes not, the arguments/evidence of Chicago people on specific elements of the question might be of great value in helping me figure out which ones are which. And so the original point remains: the existence of valuable advisers who are not good guides.
I don’t think this phenomenon is rare at all. I think in economics alone there are many insights in many fields that are now regarded to be extremely valuable for clarifying elements of big questions, but whose originators combined those insights with a great deal of wrongness, arrived at wrong final conclusions, and nevertheless were heeded on the final questions based on their insight into the specific elements.
I take your point to be that I have taken something that is really a matter of degree “how much weight should I give to the opinion of this or that person?” and turned it into something dichotomous “is this person a good guide for me or not?”
You have. To quote from your article:
One kind of adviser is someone whose opinion, by your lights, constitutes strong evidence regarding the answer...But they are only providers of valuable input, not good guides. I think the distinction between these two types of advisers is often missed...The point is that there should be two buckets for two different types of prestigious advice-giver, but we only really have one.
When I boil down your post+comment and look for sense, what I get is something prosaic like ‘some people are so expert in a narrow area that their opinion alone is enough for me, but otherwise aren’t very good on average; other people are that expert, but in a broader area’.
The point is that these are two very different kinds of valuable advisers, but the distinction is often missed.
And while I do think in real life there is something of a dichotomy between “people whose final judgment I trust on questions like X,” and “people whose final judgment I don’t trust but who I still want to hear what they have to say,” I think a similar point could be made with more than two categories.
Perhaps you mean to divide the population into the following three categories: (1) people who can convince you without argument, (2) people who can convince you with argument, and (3) people who can’t convince you even with argument; and the thesis of the post is “Not everyone in (2) is in (1)”.
This reads like a glorification of quantitative differences into a qualitative difference. Why reify this guide/portfolio distinction?
And why is that?
Is that because they are literally as wrong as they are right, that they are competitive only with a random number generator/max-ent predictor? If they are, then that’s a very peculiar sort of insight they are offering; why do you think you are free of the crippling biases that apparently reduce their otherwise insightful analyses to random noise?
Is it because they are only somewhat more right than wrong, but they do beat random guesses? Then knowing their opinion should move your decision somewhat. (Do they not move your decision at all? But we specified they were better than randomness, and so ignoring their opinion is throwing away some amount of information.) But then, they are also somewhat equivalent to your guide—but only somewhat.
I don’t think this is a well written article, but
is not right. OP might ignore them because his knowledge screens all the information in their opinions. For example, that might be true if he had studied relevant topics and was already an expert in Industrial Organization.
I think the OP’s point would be better said as something like “you should only update your probabilities when a person’s opinion gives additional information rather than when they are an expert.”
I take your point to be that I have taken something that is really a matter of degree “how much weight should I give to the opinion of this or that person?” and turned it into something dichotomous “is this person a good guide for me or not?” Here is my response.
Let’s start by imagining that you can only hear the final opinions of the different advisers, and cannot discuss with them their arguments or evidence relating to the different elements of the question. In that case, the final opinion of anyone who has a valuable insight into any element of the question ought, all else equal, to move the needle for you at least a little bit. But it may be only a very little bit, and it can perfectly well be zero. In the Chicago School example, there are categories of firm conduct that Chicago people think should basically always be permitted, but that people like me think should sometimes be permitted and sometimes not. In those cases, merely knowing the final opinion of a Chicago person about a particular variety of conduct helps me not at all. Another way to get from “X’s opinion should move you a very little bit” to “X’s opinion should move you not at all” by throwing in a small fixed cost of the consultation.
But regardless of whether the adviser’s final opinion moves you not at all or a little bit, the point is that there can still be a lot of value in hearing their arguments/evidence on particular points. If there are things that firms do that Chicago people think should always be permitted, but that people like me think should sometimes be permitted and sometimes not, the arguments/evidence of Chicago people on specific elements of the question might be of great value in helping me figure out which ones are which. And so the original point remains: the existence of valuable advisers who are not good guides.
I don’t think this phenomenon is rare at all. I think in economics alone there are many insights in many fields that are now regarded to be extremely valuable for clarifying elements of big questions, but whose originators combined those insights with a great deal of wrongness, arrived at wrong final conclusions, and nevertheless were heeded on the final questions based on their insight into the specific elements.
You have. To quote from your article:
When I boil down your post+comment and look for sense, what I get is something prosaic like ‘some people are so expert in a narrow area that their opinion alone is enough for me, but otherwise aren’t very good on average; other people are that expert, but in a broader area’.
The point is that these are two very different kinds of valuable advisers, but the distinction is often missed.
And while I do think in real life there is something of a dichotomy between “people whose final judgment I trust on questions like X,” and “people whose final judgment I don’t trust but who I still want to hear what they have to say,” I think a similar point could be made with more than two categories.
Perhaps you mean to divide the population into the following three categories: (1) people who can convince you without argument, (2) people who can convince you with argument, and (3) people who can’t convince you even with argument; and the thesis of the post is “Not everyone in (2) is in (1)”.