mattnewport

Karma: 4,176

mattnewport 12 Jul 2011 15:40 UTC
0 points
in reply to: chatquitevoit’s comment on: How I Lost 100 Pounds Using TDT

I simply say to them “Er, human technology has progressed to the point where I can have, say, a sweet breakfast without consuming any sugar, and I’m going to do so. Cheating has nothing to do with it.”

It’s true that artificial sweeteners mean you can get a sweet taste without consuming calories. Beware the conclusion that they therefore don’t cause you to gain weight or have other negative health effects though. There’s plenty of evidence to the contrary.

I agree that eating healthily doesn’t mean having to deprive yourself of all delicious foods. Sadly artificial sweeteners seem to be quite problematic, though some types may be less bad than others.

mattnewport 8 Jul 2011 20:10 UTC
4 points
in reply to: Scott Alexander’s comment on: Time and Effort Discounting
I’m not sure you need uncertainty to discount at all—in finance exponential discounting comes from interest rates which are predicated on an assumption of somewhat stable economic growth rather than deriving from uncertainty.

As you point out, hyperbolic discounting can come from combining exponential discounting with an uncertain hazard rate. It seems many of the studies on hyperbolic discounting assume they are measuring a utility function directly when they may in fact be measuring the combination of a utility function with reasonable assumptions about the uncertainty of claiming a reward. It’s not clear to me that they have actually shown that humans have time inconsistent preferences rather than just establishing that people don’t separate the utility they attach to a reward from their expectation of actually receiving it in their responses to these kinds of studies.
What links here?
- Scott Alexander's comment on Time and Effort Discounting by Scott Alexander (8 Jul 2011 21:00 UTC; 4 points)

mattnewport 8 Jul 2011 2:01 UTC
17 points
on: Time and Effort Discounting
Do any of the studies on hyperbolic discounting attempt to show that it is not just a consequence of combining uncertainty with something like a standard exponential discounting function? That’s always seemed the most plausible explanation of hyperbolic discounting to me and it meshes with what seems to be going on when I introspect on these kinds of choices.

Most of the discussions of hyperbolic discounting I see don’t even consider how increasing uncertainty for more distant rewards should factor into preferences. Ignoring uncertainty seems like it would be a sub-optimal strategy for agents making decisions in the real world.

mattnewport 4 Jan 2011 14:01 UTC
0 points
in reply to: mwengler’s comment on: New Year’s Predictions Thread
There’s room for debate whether we saw a true currency crisis in the Euro but ‘this prediction has failed utterly’ is overstating it. We saw unusually dramatic short term moves in the Euro in May and there was widespread talk about the future of the Euro being uncertain. Questions about the long term viability of the Euro continue to be raised.

I’d argue that charting any of the major currencies against gold indicates an ongoing loss of confidence in all of them—from this perspective the dollar and the euro have both declined in absolute value over the year while trading places in terms of relative value in response to changing perceptions of which one faces the biggest problems.

‘Currency crisis’ was in retrospect a somewhat ambiguous prediction to make since there is no clear criteria for establishing what constitutes one. I’d argue that the euro underwent the beginnings of a currency crisis in May but that the unprecedented intervention by the ECB forestalled a full blown currency crisis.

mattnewport 1 Dec 2010 22:49 UTC
3 points
in reply to: Meryseshat’s comment on: The Sacred Mundane
According to this article a sense of vibration and rapid acceleration of the body are fairly commonly reported (I don’t recall experiencing these symptoms myself). That article and the Wikipedia entry both mention some of the mythology and folklore surrounding the experience from different cultures.

mattnewport 28 Oct 2010 0:56 UTC
0 points
in reply to: Craig_Heldreth’s comment on: Dealing with the high quantity of scientific error in medicine
Paleo diets generally consider corn a grain so you might want to avoid that. Some paleo variants (like the one I’m currently following) are ok with cheese and yogurt in moderation (and butter).

mattnewport 27 Oct 2010 1:01 UTC
0 points
in reply to: byrnema’s comment on: Dealing with the high quantity of scientific error in medicine
I would guess this is not true in general since many things do not want to be eaten and so evolve various defense mechanisms. In turn the organisms that eat them may develop counter-measures that enable them to safely digest their meal despite the defense mechanisms but this will depend on the complex evolutionary history of both organisms. Ruminants are adapted to a quite different diet than humans for example.

mattnewport 27 Oct 2010 0:38 UTC
1 point
in reply to: byrnema’s comment on: Dealing with the high quantity of scientific error in medicine

I wonder why an apple should be healthy. Wouldn’t any animal be satisfied with a fruit that just had calories? Enough, in any case, to come back for more and scatter the seeds? Why should an apple—or anything ‘natural’—be so especially healthy for humans?

You’re missing the other side of the story. Humans evolved to obtain their nutritional needs from those foods that were available in the EEA and this effect is probably more significant than the selection pressure in the other direction (on fruits to be nutritionally beneficial to animals that eat them). Humans are adapted to a diet that includes things that were available to them during the long pre-agricultural evolutionary period.

mattnewport 15 Oct 2010 19:08 UTC
4 points
in reply to: Vladimir_M’s comment on: Love and Rationality: Less Wrongers on OKCupid
You’re probably right but ironically I’ve ignored much of the standard advice on employment and it’s worked out just fine for me so this example doesn’t resonate very well for me. I’ve never worn a suit to a job interview for example.

mattnewport 15 Oct 2010 19:07 UTC
7 points
in reply to: Relsqui’s comment on: Love and Rationality: Less Wrongers on OKCupid
I assumed he was saying something like “the majority of women prefer a man more ‘masculine’ than the median man”. By analogy, if it is true that “the majority of men prefer a woman who is slimmer than the median woman” it should be obvious that being overweight will make it harder for a woman to find a match even if there are men who prefer less slim women. Saying “men prefer slim women” is a slightly sloppy generalization but not an unreasonable one in this example.

mattnewport 15 Oct 2010 18:31 UTC
5 points
in reply to: Relsqui’s comment on: Love and Rationality: Less Wrongers on OKCupid

This confuses me, because it seems to imply that men need to believe that a simple personality heuristic can be applied to all or almost all women. Why is it an unacceptable answer that some women like one thing, and some like another?

The prevalence of different personality types in the population is very relevant here and you seem to be glossing over it. If the number of women attracted to your personality type is relatively low (and especially if it is low relative to the number of other men similar to you) it will still be an obstacle you need to overcome in finding a partner even if you believe that there are women out there who would be attracted to you. Internet dating has probably helped with this a bit by making it easier to find potential matches but it can’t overcome seriously unfavourable relative numbers.

mattnewport 15 Oct 2010 16:07 UTC
4 points
in reply to: [deleted]’s comment on: Love and Rationality: Less Wrongers on OKCupid
I think there’s a bit more to it than just women overlooking a lack of values because of other attractive factors like confidence. There’s some evidence that men with the ‘dark triad’ personality traits are more successful with women.

mattnewport 15 Oct 2010 1:26 UTC
2 points
in reply to: Relsqui’s comment on: Love and Rationality: Less Wrongers on OKCupid
I wonder how many potential matches know enough maths to realize why he used powers of two?

mattnewport 14 Oct 2010 1:00 UTC
5 points
in reply to: cousin_it’s comment on: Love and Rationality: Less Wrongers on OKCupid
A dealbreaker is something that on its own automatically rules someone out. A factor is something that swings the overall impression positively or negatively but is not on its own a deciding factor independent of other factors.

mattnewport 12 Oct 2010 3:51 UTC
3 points
in reply to: Relsqui’s comment on: Love and Rationality: Less Wrongers on OKCupid
I agree the choices aren’t ideal but I think “likes children”, “dislikes children” and “doesn’t want children” all match a search for “Doesn’t have children” whereas leaving the question blank or answering that you have children means you won’t show up in a search that specifies “Doesn’t have children”. It’s a bit confusing and not a very logical setup but I think that’s how it works.

mattnewport 11 Oct 2010 22:59 UTC
5 points
on: Love and Rationality: Less Wrongers on OKCupid

I’ve left the “children” field blank, for example, because I don’t want them now but might some day, so neither “wants” nor “doesn’t want” is correct.

I think this might be a mistake. I usually specify “Doesn’t have children” when I do a match search and I’d guess this is fairly common. If you leave this question blank I believe you won’t show up for people who are filtering on that search criteria.

mattnewport 6 Oct 2010 17:40 UTC
1 point
in reply to: blogospheroid’s comment on: The Irrationality Game
Historically, global population increase has correlated pretty well with increases in measures of overall health, wealth and quality of life. What empirical evidence do you derive your theory that zero or negative population growth would be better for these measures from?

mattnewport 5 Oct 2010 20:22 UTC
0 points
in reply to: Vladimir_M’s comment on: The Irrationality Game

I just don’t see any practical examples of people successfully betting by doing calculations with probability numbers derived from their intuitive feelings of confidence that would go beyond what a mere verbal expression of these feelings would convey. Can you think of any?

I’d speculate that bookies and professional sports bettors are doing something like this. By bookies here I mean primarily the kind of individuals who stand with a chalkboard at race tracks rather than the large companies. They probably use some semi-rigorous / scientific techniques to analyze past form and then mix it with a lot of intuition / expertise together with lots of detailed domain specific knowledge and ‘insider’ info (a particular horse or jockey has recently recovered from an illness or injury and so may perform worse than expected, etc.). They’ll then integrate all of this information together using some non mathematically rigorous opaque mental process and derive a probability estimate which will determine what odds they are willing to offer or accept.

I’ve read a fair bit of material by professional investors and macro hedge fund managers describing their thinking and how they make investment decisions. I think they are often doing something similar. Integrating information derived from rigorous analysis with more fuzzy / intuitive reasoning based on expertise, knowledge and experience and using it to derive probabilities for particular outcomes. They then seek out investments that currently appear to be mis-priced relative to the probabilities they’ve estimated, ideally with a fairly large margin of safety to allow for the imprecise and uncertain nature of their estimates.

It’s entirely possible that this is not what’s going on at all but it appears to me that something like this is a factor in the success of anyone who consistently profits from dealing with risk and uncertainty.

The problem with discussing investment strategies is that any non-trivial public information about this topic necessarily has to be bullshit, or at least drowned in bullshit to the point of being irrecoverable, since exclusive possession of correct information is a sure path to getting rich, but its effectiveness critically depends on exclusivity.

My experience leads me to believe that this is not entirely accurate. Investors are understandably reluctant to share very specific time critical investment ideas for free but they frequently share their thought processes for free and talk in general terms about their approaches and my impression is that they are no more obfuscatory or deliberately misleading than anyone else who talks about their success in any field.

In addition, hedge fund investor letters often share quite specific details of reasoning after the fact once profitable trades have been closed and these kinds of details are commonly elaborated in books and interviews once time-sensitive information has lost most of its value.

Either your “rationality” manifests itself only in irrelevant matters, or you have to ask yourself what is so special and exclusive about you that you’re reaping practical success that eludes so many other people, and in such a way that they can’t just copy your approach.

This seems to be taking the ethos of the EMH a little far. I comfortably attribute a significant portion of my academic and career success to being more intelligent and a clearer thinker than most people. Anyone here who through a sense of false modesty believes otherwise is probably deluding themselves.

Where your own individual judgment falls within this picture, you cannot know, unless you’re one of these people with esoteric expertise.

This seems to be the main point of ongoing calibration exercises. If you have a track record of well calibrated predictions then you can gain some confidence that your own individual judgement is sound.

Overall I don’t think we have a massive disagreement here. I agree with most of your reservations and I’m by no means certain that improving one’s own calibration is feasible but I suspect that it might be and it seems sufficiently instrumentally useful that I’m interested in trying to improve my own.

mattnewport 5 Oct 2010 2:53 UTC
0 points
in reply to: DanielLC’s comment on: The Irrationality Game
I expected the third to be higher than most less wrongers would estimate.

mattnewport 5 Oct 2010 0:06 UTC
0 points
in reply to: Vladimir_M’s comment on: The Irrationality Game

In reality, it is rational to bet only with people over whom you have superior relevant knowledge, or with someone who is suffering from an evident failure of common sense.

You still have to be able to translate your superior relevant knowledge into odds in order to set the terms of the bet however. Do you not believe that this is an ability that people have varying degrees of aptitude for?

Look at the stock market: it’s pure gambling, unless you have insider knowledge or vastly higher expertise than the average investor.

Vastly higher expertise than the average investor would appear to include something like the ability in question—translating your beliefs about the future into a probability such that you can judge whether investments have positive expected value. If you accept that true alpha) exists (and the evidence suggests that though rare a small percentage of the best investors do appear to have positive alpha) then what process do you believe those who possess it use to decide which investments are good and which bad?

What’s your opinion on prediction markets? They seem to produce fairly good probability estimates so presumably the participants must be using some better-than-random process for arriving at numerical probability estimates for their predictions.

I’m not familiar with the details of this business, but from what I understand, bookmakers work in such a way that they’re guaranteed to make a profit no matter what happens.

They certainly aim for a balanced book but they wouldn’t be very profitable if they were not reasonably competent at setting initial odds (and updating them in the light of new information). If the initial odds are wildly out of line with their customers’ then they won’t be able to make a balanced book.