“But I tell you he couldn’t have written such a note!” cried Flambeau. “The note is utterly wrong about the facts. And innocent or guilty, Dr Hirsch knew all about the facts.”
“The man who wrote that note knew all about the facts,” said his clerical companion soberly. “He could never have got ‘em so wrong without knowing about ’em. You have to know an awful lot to be wrong on every subject—like the devil.”
“Do you mean—?”
“I mean a man telling lies on chance would have told some of the truth,” said his friend firmly. “Suppose someone sent you to find a house with a green door and a blue blind, with a front garden but no back garden, with a dog but no cat, and where they drank coffee but not tea. You would say if you found no such house that it was all made up. But I say no. I say if you found a house where the door was blue and the blind green, where there was a back garden and no front garden, where cats were common and dogs instantly shot, where tea was drunk in quarts and coffee forbidden—then you would know you had found the house. The man must have known that particular house to be so accurately inaccurate.”
If someone tells you the opposite of the truth in order to deceive you, and you believe the opposite of what they say because you know they are deceitful, then you believe the truth. (A knave is as good as a knight to a blind bat.) The problem is, a clever liar doesn’t lie all the time, but only when it matters.
Another problem is that for many interesting assertions X, opposite(opposite(X)) does not necessarily equal X. Indeed, opposite(opposite(X)) frequently implies NOT X.
Could you give an example? I would have thought this happens with Not(opposite(X)); for example, “I don’t hate you” is different than “I love you”, and in fact implies that I don’t. But I would have thought “opposite” was symmetric, so opposite(opposite(X)) = X.
Well, OK. So suppose (to stick with your example) I love you, and I want to deceive you about it by expressing the opposite of what I feel. So what do I say?
You seem to take for granted that opposite(“I love you”) = “I hate you.” And not, for example, “I am indifferent to you.” Or “You disgust me.” Or various other assertions. And, sure, if “I love you” has a single, unambiguous opposite, and the opposite also has a single, unambiguous opposite, then my statement is false. But it’s not clear to me that this is true.
If I end up saying “I’m indifferent to you” and you decide to believe the opposite of that… well, what do you believe?
Of course, simply negating the truth (“I don’t love you”) is unambiguously arrived at, and can be thought of as an opposite… though in practice, that’s often not what I actually do when I want to deceive someone, unless I’ve been specifically accused of the truth. (“We’re not giant purple tubes from outer space!”)
Lol, my professor would give a 100% to anyone who answered every exam question wrong. There were a couple people who pulled it off, but most scored 0<10.
I’m assuming a multiple-choice exam, and invalid answers don’t count as ‘wrong’ for that purpose?
Otherwise I can easily miss the entire exam with “Tau is exactly six.” or “The battle of Thermopylae” repeated for every answer. Even if the valid answers are [A;B;C;D].
I hate to break up the fun, and I’m sure we could keep going on about this, but Decius’s original point was just that giving a wrong answer to an open-ended question is trivially easy. We can play word games and come up with elaborate counter-factuals, but the substance of that point is clearly correct, so maybe we should just move on.
That was exactly the challenge I issued. Granted, it’s trivial to write an answer which is wrong for that question, but it shows that I can’t find a wrong answer for an arbitrary question as easily as I thought I could.
An interesting corollary of the efficient market hypothesis is that, neglecting overhead due to things like brokerage fees and assuming trades are not large enough to move the market, it should be just as difficult to lose money trading securities as it is to make money.
No, not really. In an efficient marked risks uncorrelated with those of other securities shouldn’t be compensated, so you should easily be able to screw yourself over by not diversifying.
But isn’t the risk of diversifying compensated by a corresponding possibility of large reward if the sector outperforms? I wouldn’t consider a strategy that produces modest losses with high probability but large gains with low probability sufficient to disprove my claim.
Let’s go one step back on this, because I think our point of disagreement is earlier than I thought in that last comment.
The efficient market hypothesis does not claim that the profit on all securities has the same expectation value. EMH-believers don’t deny, for example, the empirically obvious fact that this expectation value is higher for insurances than for more predictable businesses. Also, you can always increase your risk and expected profit by leverage, i.e. by investing borrowed money.
This is because markets are risk-averse, so that on the same expectation value you get payed extra to except a higher standard deviation. Out- or underperforming the market is really easy by excepting more or less risk than it does on average. The claim is not that the expectation value will be the same for every security, only that the price of every security will be consistent with the same prices for risk and expected profit.
So if the EMH is true, you can not get a better deal on expected profit without also accepting higher risk and you can not get a higher risk premium than other people. But you still can get lots of different trade-offs between expected profit and risk.
Now can you do worse? Yes, because you can separate two types of risk.
Some risks are highly specific to individual companies. For example, a company may be in trouble if a key employee gets hit by a beer truck. That’s uncorrelated risk. Other risks affect the whole economy, like revolutions, asteroids or the boom-bust-cycle. That’s correlated risk.
Diversification can insure you against uncorrelated risk, because, by definition, it’s independent from the risk of other parts of your portfolio, so it’s extremely unlikely for many of your diverse investments to be affected at the same time. So if everyone is properly diversified, no one actually needs to bear uncorrelated risk. In an efficient market that means it doesn’t earn any compensation.
Correlated risk is not eliminated by diversification, because it is by definition the risk that affects all your diversified investments simultaneously.
So if you don’t diversify you are taking on uncorrelated risk without getting paid for it. If you do that you could get a strictly better deal by taking on a correlated risk of the same magnitude which you would get payed for. And since that is what the marked is doing on average, you can get a worse deal than it does.
There is an episode of Seinfeld where George—a lifelong screw up—decides to do the opposite of his natural instincts and impulses at every turn. He has a great day, lands his job at the Yankees, etc.
I was a superb Onslaught drafter, but there was probably a reason my buddy Scott had a dim confidence in my game play. So I decided to draft normally but pull a George and do the opposite of everything I was inclined to in game.
The result was a Day 2 with a terrible Sealed deck and 3-0 / 6-0 in my first draft. I needed 2-1 for Top 8.
The “Even Steven” part is that at that point I was so full of myself I forgot to do the opposite of what I wanted to do and made about three important mistakes… Exactly enough to land myself one point out of Top 8 at Grand Prix Boston (Kibler won).
The late (or at least severely delayed) Bergholt Stuttley Johnson was generally recognized as the worst inventor in the
world, yet in a very specialized sense. Merely bad inventors made things that failed to operate. He wasn’t among these small fry. Any fool could make something that did absolutely nothing when you pressed the button. He scorned such fumble-fingered amateurs. Everything he built worked. It just didn’t do what it said on the box. If you wanted a small ground-to-air missile, you asked Johnson to design an ornamental fountain.
This reminds me of an episode of QI, in which Johnny Vegas, who usually throws out random answers for the humor, actually managed to get a question (essentially) right.
Ken Wilber
--G.K. Chesterton, “The Duel of Dr. Hirsch”
Reversed malevolence is intelligence?
Inverted information is not random noise.
...unless you’re reversing noise which is why Reverse Stupidity is not Intelligence.
If someone tells you the opposite of the truth in order to deceive you, and you believe the opposite of what they say because you know they are deceitful, then you believe the truth. (A knave is as good as a knight to a blind bat.) The problem is, a clever liar doesn’t lie all the time, but only when it matters.
It’s more likely that they’re a stupid liar than that they got it all wrong by chance.
Another problem is that for many interesting assertions X, opposite(opposite(X)) does not necessarily equal X. Indeed, opposite(opposite(X)) frequently implies NOT X.
Could you give an example? I would have thought this happens with Not(opposite(X)); for example, “I don’t hate you” is different than “I love you”, and in fact implies that I don’t. But I would have thought “opposite” was symmetric, so opposite(opposite(X)) = X.
Well, OK. So suppose (to stick with your example) I love you, and I want to deceive you about it by expressing the opposite of what I feel. So what do I say?
You seem to take for granted that opposite(“I love you”) = “I hate you.” And not, for example, “I am indifferent to you.” Or “You disgust me.” Or various other assertions. And, sure, if “I love you” has a single, unambiguous opposite, and the opposite also has a single, unambiguous opposite, then my statement is false. But it’s not clear to me that this is true.
If I end up saying “I’m indifferent to you” and you decide to believe the opposite of that… well, what do you believe?
Of course, simply negating the truth (“I don’t love you”) is unambiguously arrived at, and can be thought of as an opposite… though in practice, that’s often not what I actually do when I want to deceive someone, unless I’ve been specifically accused of the truth. (“We’re not giant purple tubes from outer space!”)
Lol, my professor would give a 100% to anyone who answered every exam question wrong. There were a couple people who pulled it off, but most scored 0<10.
I’m assuming a multiple-choice exam, and invalid answers don’t count as ‘wrong’ for that purpose?
Otherwise I can easily miss the entire exam with “Tau is exactly six.” or “The battle of Thermopylae” repeated for every answer. Even if the valid answers are [A;B;C;D].
Unless it really was the battle of Thermopylae. Not having studied, you wont know.
“The Battle of Thermopylae” is intended as the alternate for questions which might have “Tau is exactly six” as the answer.
For example: “What would be one consequence of a new state law which defines the ratio of a circle’s circumference to diameter as exactly three?”
I bet that you can’t write a question for which “Tau is exactly six.” and “The battle of Thermopylae” are both answers which gain any credit...
“Write a four word phrase or sentence.”
You win.
Judging by this and your previous evil genie comments, you’d make a lovely UFAI.
I hate to break up the fun, and I’m sure we could keep going on about this, but Decius’s original point was just that giving a wrong answer to an open-ended question is trivially easy. We can play word games and come up with elaborate counter-factuals, but the substance of that point is clearly correct, so maybe we should just move on.
That was exactly the challenge I issued. Granted, it’s trivial to write an answer which is wrong for that question, but it shows that I can’t find a wrong answer for an arbitrary question as easily as I thought I could.
“The duel between the current King of France and the former Emperor of Britain”. There, the answer won’t ever be that phrase.
What if you are in a literature class and you’re taking a test about a fiction book you didn’t read?
Care to bet on that?
An interesting corollary of the efficient market hypothesis is that, neglecting overhead due to things like brokerage fees and assuming trades are not large enough to move the market, it should be just as difficult to lose money trading securities as it is to make money.
No, not really. In an efficient marked risks uncorrelated with those of other securities shouldn’t be compensated, so you should easily be able to screw yourself over by not diversifying.
But isn’t the risk of diversifying compensated by a corresponding possibility of large reward if the sector outperforms? I wouldn’t consider a strategy that produces modest losses with high probability but large gains with low probability sufficient to disprove my claim.
Let’s go one step back on this, because I think our point of disagreement is earlier than I thought in that last comment.
The efficient market hypothesis does not claim that the profit on all securities has the same expectation value. EMH-believers don’t deny, for example, the empirically obvious fact that this expectation value is higher for insurances than for more predictable businesses. Also, you can always increase your risk and expected profit by leverage, i.e. by investing borrowed money.
This is because markets are risk-averse, so that on the same expectation value you get payed extra to except a higher standard deviation. Out- or underperforming the market is really easy by excepting more or less risk than it does on average. The claim is not that the expectation value will be the same for every security, only that the price of every security will be consistent with the same prices for risk and expected profit.
So if the EMH is true, you can not get a better deal on expected profit without also accepting higher risk and you can not get a higher risk premium than other people. But you still can get lots of different trade-offs between expected profit and risk.
Now can you do worse? Yes, because you can separate two types of risk.
Some risks are highly specific to individual companies. For example, a company may be in trouble if a key employee gets hit by a beer truck. That’s uncorrelated risk. Other risks affect the whole economy, like revolutions, asteroids or the boom-bust-cycle. That’s correlated risk.
Diversification can insure you against uncorrelated risk, because, by definition, it’s independent from the risk of other parts of your portfolio, so it’s extremely unlikely for many of your diverse investments to be affected at the same time. So if everyone is properly diversified, no one actually needs to bear uncorrelated risk. In an efficient market that means it doesn’t earn any compensation.
Correlated risk is not eliminated by diversification, because it is by definition the risk that affects all your diversified investments simultaneously.
So if you don’t diversify you are taking on uncorrelated risk without getting paid for it. If you do that you could get a strictly better deal by taking on a correlated risk of the same magnitude which you would get payed for. And since that is what the marked is doing on average, you can get a worse deal than it does.
Unless you’re a fictional character. Or possibly Mike “Bad Player” Flores:
I thought your first link would be Bloody Stupid Johnson.
This reminds me of an episode of QI, in which Johnny Vegas, who usually throws out random answers for the humor, actually managed to get a question (essentially) right.