[Link] "Fewer than X% of Americans know Y"

36 Nisan 10 October 2012 04:59PM

How many times have you heard a claim from a somewhat reputable source like "only 28 percent of Americans are able to name one of the constitutional freedoms, yet 52 percent are able to name at least two Simpsons family members"?

Mark Liberman over at Language Log wrote up a post showing how even when such claims are based on actual studies, the methodology is biased to exaggerate ignorance:

The way it works is that the survey designers craft a question like the following (asked at a time when William Rehnquist was the Chief Justice of the United States):

"Now we have a set of questions concerning various public figures. We want to see how much information about them gets out to the public from television, newspapers and the like….
What about William Rehnquist – What job or political office does he NOW hold?"

The answers to such open-ended questions are recorded — as audio recordings and/or as notes taken by the interviewer — and these records are coded, later on, by hired coders.

The survey designers give these coders very specific instructions about what counts as right and wrong in the answers. In the case of the question about William Rehnquist, the criteria for an answer to be judged correct were mentions of both "chief justice" and "Supreme Court". These terms had to be mentioned explicitly, so all of the following (actual answers) were counted as wrong:

Supreme Court justice. The main one.
He’s the senior judge on the Supreme Court.
He is the Supreme Court justice in charge.
He’s the head of the Supreme Court.
He’s top man in the Supreme Court.
Supreme Court justice, head.
Supreme Court justice. The head guy.
Head of Supreme Court.
Supreme Court justice head honcho.

Similarly, the technically correct answer ("Chief Justice of the United States") would also have been scored as wrong (I'm not certain whether it actually occurred or not in the survey responses).

If, every time you heard a claim of the form "Only X% of Americans know Y" you thought "there's something strange about that", then you get 1 rationality point. If you thought "I don't believe that", then you get 2 rationality points.

 

Causal Diagrams and Causal Models

61 Eliezer_Yudkowsky 12 October 2012 09:49PM

Suppose a general-population survey shows that people who exercise less, weigh more. You don't have any known direction of time in the data - you don't know which came first, the increased weight or the diminished exercise. And you didn't randomly assign half the population to exercise less; you just surveyed an existing population.

The statisticians who discovered causality were trying to find a way to distinguish, within survey data, the direction of cause and effect - whether, as common sense would have it, more obese people exercise less because they find physical activity less rewarding; or whether, as in the virtue theory of metabolism, lack of exercise actually causes weight gain due to divine punishment for the sin of sloth.

 vs. 

The usual way to resolve this sort of question is by randomized intervention. If you randomly assign half your experimental subjects to exercise more, and afterward the increased-exercise group doesn't lose any weight compared to the control group [1], you could rule out causality from exercise to weight, and conclude that the correlation between weight and exercise is probably due to physical activity being less fun when you're overweight [3]. The question is whether you can get causal data without interventions.

For a long time, the conventional wisdom in philosophy was that this was impossible unless you knew the direction of time and knew which event had happened first. Among some philosophers of science, there was a belief that the "direction of causality" was a meaningless question, and that in the universe itself there were only correlations - that "cause and effect" was something unobservable and undefinable, that only unsophisticated non-statisticians believed in due to their lack of formal training:

"The law of causality, I believe, like much that passes muster among philosophers, is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm." -- Bertrand Russell (he later changed his mind)

"Beyond such discarded fundamentals as 'matter' and 'force' lies still another fetish among the inscrutable arcana of modern science, namely, the category of cause and effect." -- Karl Pearson

The famous statistician Fisher, who was also a smoker, testified before Congress that the correlation between smoking and lung cancer couldn't prove that the former caused the latter.  We have remnants of this type of reasoning in old-school "Correlation does not imply causation", without the now-standard appendix, "But it sure is a hint".

This skepticism was overturned by a surprisingly simple mathematical observation.

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Firewalling the Optimal from the Rational

86 Eliezer_Yudkowsky 08 October 2012 08:01AM

Followup to: Rationality: Appreciating Cognitive Algorithms  (minor post)

There's an old anecdote about Ayn Rand, which Michael Shermer recounts in his "The Unlikeliest Cult in History" (note: calling a fact unlikely is an insult to your prior model, not the fact itself), which went as follows:

Branden recalled an evening when a friend of Rand's remarked that he enjoyed the music of Richard Strauss. "When he left at the end of the evening, Ayn said, in a reaction becoming increasingly typical, 'Now I understand why he and I can never be real soulmates. The distance in our sense of life is too great.' Often she did not wait until a friend had left to make such remarks."

Many readers may already have appreciated this point, but one of the Go stones placed to block that failure mode is being careful what we bless with the great community-normative-keyword 'rational'. And one of the ways we do that is by trying to deflate the word 'rational' out of sentences, especially in post titles or critical comments, which can live without the word.  As you hopefully recall from the previous post, we're only forced to use the word 'rational' when we talk about the cognitive algorithms which systematically promote goal achievement or map-territory correspondences.  Otherwise the word can be deflated out of the sentence; e.g. "It's rational to believe in anthropogenic global warming" goes to "Human activities are causing global temperatures to rise"; or "It's rational to vote for Party X" deflates to "It's optimal to vote for Party X" or just "I think you should vote for Party X".

If you're writing a post comparing the experimental evidence for four different diets, that's not "Rational Dieting", that's "Optimal Dieting". A post about rational dieting is if you're writing about how the sunk cost fallacy causes people to eat food they've already purchased even if they're not hungry, or if you're writing about how the typical mind fallacy or law of small numbers leads people to overestimate how likely it is that a diet which worked for them will work for a friend. And even then, your title is 'Dieting and the Sunk Cost Fallacy', unless it's an overview of four different cognitive biases affecting dieting. In which case a better title would be 'Four Biases Screwing Up Your Diet', since 'Rational Dieting' carries an implication that your post discusses the cognitive algorithm for dieting, as opposed to four contributing things to keep in mind.

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Causality: a chapter by chapter review

54 Vaniver 26 September 2012 04:55PM

This is a chapter by chapter review of Causality (2nd ed.) by Judea Pearl (UCLA, blog). Like my previous review, the intention is not to summarize but to help readers determine whether or not they should read the book (and if they do, what parts to read). Reading the review is in no way a substitute for reading the book.

I'll state my basic impression of the book up front, with detailed comments after the chapter discussions: this book is monumentally important to anyone interested in procuring knowledge (especially causal knowledge) from statistical data, but it is a heavily technical book primarily suitable for experts. The mathematics involved is not particularly difficult, but its presentation requires dedicated reading and clarity of thought. Only the epilogue, this lecture, is suitable for the general audience, and that will be the highest value portion for most readers of LW.

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Debugging the Quantum Physics Sequence

32 Mitchell_Porter 05 September 2012 03:55PM

This article should really be called "Patching the argumentative flaw in the Sequences created by the Quantum Physics Sequence".

There's only one big thing wrong with that Sequence: the central factual claim is wrong. I don't mean the claim that the Many Worlds interpretation is correct; I mean the claim that the Many Worlds interpretation is obviously correct. I don't agree with the ontological claim either, but I especially don't agree with the epistemological claim. It's a strawman which reduces the quantum debate to Everett versus Bohr - well, it's not really Bohr, since Bohr didn't believe wavefunctions were physical entities. Everett versus Collapse, then.

I've complained about this from the beginning, simply because I've also studied the topic and profoundly disagree with Eliezer's assessment. What I would like to see discussed on this occasion is not the physics, but rather how to patch the arguments in the Sequences that depend on this wrong sub-argument. To my eyes, this is a highly visible flaw, but it's not a deep one. It's a detail, a bug. Surely it affects nothing of substance.

However, before I proceed, I'd better back up my criticism. So: consider the existence of single-world retrocausal interpretations of quantum mechanics, such as John Cramer's transactional interpretation, which is descended from Wheeler-Feynman absorber theory. There are no superpositions, only causal chains running forward in time and backward in time. The calculus of complex-valued probability amplitudes is supposed to arise from this.

The existence of the retrocausal tradition already shows that the debate has been represented incorrectly; it should at least be Everett versus Bohr versus Cramer. I would also argue that when you look at the details, many-worlds has no discernible edge over single-world retrocausality:

  • Relativity isn't an issue for the transactional interpretation: causality forwards and causality backwards are both local, it's the existence of loops in time which create the appearance of nonlocality.
  • Retrocausal interpretations don't have an exact derivation of the Born rule, but neither does many-worlds.
  • Many-worlds finds hope of such a derivation in a property of the quantum formalism: the resemblance of density matrix entries to probabilities. But single-world retrocausality finds such hope too: the Born probabilities can be obtained from the product of ψ with ψ*, its complex conjugate, and ψ* is the time reverse of ψ. 
  • Loops in time just fundamentally bug some people, but splitting worlds have the same effect on others.

I am not especially an advocate of retrocausal interpretations. They are among the possibilities; they deserve consideration and they get it. Retrocausality may or may not be an element of the real explanation of why quantum mechanics works. Progress towards the discovery of the truth requires exploration on many fronts, that's happening, we'll get there eventually. I have focused on retrocausal interpretations here just because they offer the clearest evidence that the big picture offered by the Sequence is wrong.

It's hopeless to suggest rewriting the Sequence, I don't think that would be a good use of anyone's time. But what I would like to have, is a clear idea of the role that "the winner is ... Many Worlds!" plays in the overall flow of argument, in the great meta-sequence that is Less Wrong's foundational text; and I would also like to have a clear idea of how to patch the argument, so that it routes around this flaw.

In the wiki, it states that "Cleaning up the old confusion about QM is used to introduce basic issues in rationality (such as the technical version of Occam's Razor), epistemology, reductionism, naturalism, and philosophy of science." So there we have it - a synopsis of the function that this Sequence is supposed to perform. Perhaps we need a working group that will identify each of the individual arguments, and come up with a substitute for each one.

How to deal with someone in a LessWrong meeting being creepy

16 Douglas_Reay 09 September 2012 04:41AM

One of the lessons highlighted in the thread "Less Wrong NYC: Case Study of a Successful Rationalist Chapter" is Gender ratio matters.

There have recently been a number of articles addressing one social skills issue that might be affecting this, from the perspective of a geeky/sciencefiction community with similar attributes to LessWrong, and I want to link to these, not just so the people potentially causing problems get to read them, but also so everyone else knows the resource is there and has a name for the problem, which may facilitate wider discussion and make it easier for others to know when to point towards the resources those who would benefit by them.

However before I do, in the light of RedRobot's comment in the "Of Gender and Rationality" thread, I'd like to echo a sentiment from one of the articles, that people exhibiting this behaviour may be of any gender and may victimise upon any gender.   And so, while it may be correlated with a particular gender, it is the behaviour that should be focused upon, and turning this thread into bashing of one gender (or defensiveness against perceived bashing) would be unhelpful.

Ok, disclaimers out of the way, here are the links:

Some of those raise deeper issues about rape culture and audience as enabler, but the TLDR summary is:

  1. Creepy behaviour is behaviour that tends to make others feel unsafe or uncomfortable.
  2. If a significant fraction of a group find your behaviour creepy, the responsibility to change the behaviour is yours.
  3. There are specific objective behaviours listed in the articles (for example, to do with touching, sexual jokes and following people) that even someone 'bad' at social skills can learn to avoid doing.
  4. If someone is informed that their behaviour is creeping people out, and yet they don't take steps to avoid doing these behaviours, that is a serious problem for the group as a whole, and it needs to be treated seriously and be seen to be treated seriously, especially by the 'audience' who are not being victimised directly.

EDITED TO ADD:

Despite the way some of the links are framed as being addressed to creepers, this post is aimed at least as much at the community as a whole, intended to trigger a discussion on how the community should best go about handling such a problem once identified, with the TLDR being "set of restraints to place on someone who is burning the commons", rather that a complete description that guarantees that anyone who doesn't meet it isn't creepy.  (Thank you to jsteinhardt for clearly verbalising the misinterpretation - for discussion see his reply to this post)

The noncentral fallacy - the worst argument in the world?

157 Yvain 27 August 2012 03:36AM

Related to: Leaky Generalizations, Replace the Symbol With The Substance, Sneaking In Connotations

David Stove once ran a contest to find the Worst Argument In The World, but he awarded the prize to his own entry, and one that shored up his politics to boot. It hardly seems like an objective process.

If he can unilaterally declare a Worst Argument, then so can I. I declare the Worst Argument In The World to be this: "X is in a category whose archetypal member gives us a certain emotional reaction. Therefore, we should apply that emotional reaction to X, even though it is not a central category member."

Call it the Noncentral Fallacy. It sounds dumb when you put it like that. Who even does that, anyway?

It sounds dumb only because we are talking soberly of categories and features. As soon as the argument gets framed in terms of words, it becomes so powerful that somewhere between many and most of the bad arguments in politics, philosophy and culture take some form of the noncentral fallacy. Before we get to those, let's look at a simpler example.

Suppose someone wants to build a statue honoring Martin Luther King Jr. for his nonviolent resistance to racism. An opponent of the statue objects: "But Martin Luther King was a criminal!"

Any historian can confirm this is correct. A criminal is technically someone who breaks the law, and King knowingly broke a law against peaceful anti-segregation protest - hence his famous Letter from Birmingham Jail.

But in this case calling Martin Luther King a criminal is the noncentral. The archetypal criminal is a mugger or bank robber. He is driven only by greed, preys on the innocent, and weakens the fabric of society. Since we don't like these things, calling someone a "criminal" naturally lowers our opinion of them.

The opponent is saying "Because you don't like criminals, and Martin Luther King is a criminal, you should stop liking Martin Luther King." But King doesn't share the important criminal features of being driven by greed, preying on the innocent, or weakening the fabric of society that made us dislike criminals in the first place. Therefore, even though he is a criminal, there is no reason to dislike King.

This all seems so nice and logical when it's presented in this format. Unfortunately, it's also one hundred percent contrary to instinct: the urge is to respond "Martin Luther King? A criminal? No he wasn't! You take that back!" This is why the noncentral is so successful. As soon as you do that you've fallen into their trap. Your argument is no longer about whether you should build a statue, it's about whether King was a criminal. Since he was, you have now lost the argument.

Ideally, you should just be able to say "Well, King was the good kind of criminal." But that seems pretty tough as a debating maneuver, and it may be even harder in some of the cases where the noncentral Fallacy is commonly used.

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Bayes for Schizophrenics: Reasoning in Delusional Disorders

88 Yvain 13 August 2012 07:22PM

Related to: The Apologist and the Revolutionary, Dreams with Damaged Priors

Several years ago, I posted about V.S. Ramachandran's 1996 theory explaining anosognosia through an "apologist" and a "revolutionary".

Anosognosia, a condition in which extremely sick patients mysteriously deny their sickness, occurs during right-sided brain injury but not left-sided brain injury. It can be extraordinarily strange: for example, in one case, a woman whose left arm was paralyzed insisted she could move her left arm just fine, and when her doctor pointed out her immobile arm, she claimed that was her daughter's arm even though it was obviously attached to her own shoulder. Anosognosia can be temporarily alleviated by squirting cold water into the patient's left ear canal, after which the patient suddenly realizes her condition but later loses awareness again and reverts back to the bizarre excuses and confabulations.

Ramachandran suggested that the left brain is an "apologist", trying to justify existing theories, and the right brain is a "revolutionary" which changes existing theories when conditions warrant. If the right brain is damaged, patients are unable to change their beliefs; so when a patient's arm works fine until a right-brain stroke, the patient cannot discard the hypothesis that their arm is functional, and can only use the left brain to try to fit the facts to their belief.

In the almost twenty years since Ramachandran's theory was published, new research has kept some of the general outline while changing many of the specifics in the hopes of explaining a wider range of delusions in neurological and psychiatric patients. The newer model acknowledges the left-brain/right-brain divide, but adds some new twists based on the Mind Projection Fallacy and the brain as a Bayesian reasoner.

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The Mere Cable Channel Addition Paradox

64 Ghatanathoah 26 July 2012 07:20AM

The following is a dialogue intended to illustrate what I think may be a serious logical flaw in some of the conclusions drawn from the famous Mere Addition Paradox

EDIT:  To make this clearer, the interpretation of the Mere Addition Paradox this post is intended to criticize is the belief that a world consisting of a large population full of lives barely worth living is the optimal world. That is, I am disagreeing with the idea that the best way for a society to use the resources available to it is to create as many lives barely worth living as possible.  Several commenters have argued that another interpretation of the Mere Addition Paradox is that a sufficiently large population with a lower quality of life will always be better than a smaller population with a higher quality of life, even if such a society is far from optimal.  I agree that my argument does not necessarily refute this interpretation, but think the other interpretation is common enough that it is worth arguing against.

EDIT: On the advice of some of the commenters I have added a shorter summary of my argument in non-dialogue form at the end.  Since it is shorter I do not think it summarizes my argument as completely as the dialogue, but feel free to read it instead if pressed for time.

Bob:  Hi, I'm with R&P cable.  We're selling premium cable packages to interested customers.  We have two packages to start out with that we're sure you love.  Package A+ offers a larger selection of basic cable channels and costs $50.  Package B offers a larger variety of exotic channels for connoisseurs,  it costs $100.  If you buy package A+, however, you'll get a 50% discount on B. 

Alice:  That's very nice, but looking at the channel selection, I just don't think that it will provide me with enough utilons.

Bob: Utilons?  What are those?

Alice: They're the unit I use to measure the utility I get from something.  I'm really good at shopping, so if I spend my money on the things I usually spend it on I usually get 1.5 utilons for every dollar I spend.  Now, looking at your cable channels, I've calculated that I will get 10 utilons from buying Package A+ and 100 utilons from buying Package B.  Obviously the total is 110, significantly less than the 150 utilons I'd get from spending $100 on other things.  It's just not a good deal for me.

Bob:  You think so?  Well it so happens that I've met people like you in the past and have managed to convince them.  Let me tell you about something called the "Mere Cable Channel Addition Paradox."

Alice:  Alright, I've got time, make your case.

Bob:  Imagine that the government is going to give you $50.  Sounds like a good thing, right?

Alice:  It depends on where it gets the $50 from.  What if it defunds a program I think is important?

Bob:  Let's say that it would defund a program that you believe is entirely neutral.  The harms the program causes are exactly outweighed by the benefits it brings, leaving a net utility of zero.

Alice:  I can't think of any program like that, but I'll pretend one exists for the sake of the argument.  Yes, defunding it and giving me $50 would be a good thing.

Bob:  Okay, now imagine the program's beneficiaries put up a stink, and demand the program be re-instituted.  That would be bad for you, right?

Alice:  Sure.  I'd be out $50 that I could convert into 75 utilons.

Bob:  Now imagine that the CEO of R&P Cable Company sleeps with an important senator and arranges a deal.  You get the $50, but you have to spend it on Package A+.  That would be better than not getting the money at all, right?

Alice: Sure.  10 utilons is better than zero.  But getting to spend the $50 however I wanted would be best of all.

Bob:  That's not an option in this thought experiment.  Now, imagine that after you use the money you received to buy Package A+, you find out that the 50% discount for Package B still applies.  You can get it for $50.  Good deal, right?

Alice:  Again, sure.  I'd get 100 utilons for $50. Normally I'd only get 75 utilons.

Bob:  Well, there you have it.  By a mere addition I have demonstrated that a world where you have bought both Package A+ and Package B is better than one where you have neither.  The only difference between the hypothetical world I imagined and the world we live in is that in one you are spending money on cable channels.  A mere addition.  Yet you have admitted that that world is better than this one.  So what are you waiting for?  Sign up for Package A+ and Package B!

And that's not all.  I can keep adding cable packages to get the same result.  The end result of my logic, which I think you'll agree is impeccable, is that you purchase Package Z, a package where you spend all the money other than that you need for bare subsistence on cable television packages.

Alice:  That seems like a pretty repugnant conclusion. 

Bob:  It still follows from the logic.  For every world where you are spending your money on whatever you have calculated generates the most utilons there exists another, better world where you are spending all your money on premium cable channels.

Alice:  I think I found a flaw in your logic.  You didn't perform a "mere addition."  The hypothetical world differs from ours in two ways, not one.  Namely, in this world the government isn't giving me $50.  So your world doesn't just differ from this one in terms of how many cable packages I've bought, it also differs in how much money I have to buy them.

Bob: So can I interest you in a special form of the package?  This one is in the form of a legally binding pledge.  You pledge that if you ever make an extra $50 in the future you will use it to buy Package A+.

Alice:  No.  In the scenario you describe the only reason buying Package A+ has any value is that it is impossible to get utility out of that money any other way.  If I just get $50 for some reason it's more efficient for me to spend it normally.

Bob:  Are you sure?  I've convinced a lot of people with my logic.

Alice:  Like who?

Bob:  Well, there were these two customers named Michael Huemer and Robin Hanson who both accepted my conclusion.  They've both mortgaged their homes and started sending as much money to R&P cable as they can.

Alice:  There must be some others who haven't.

Bob:  Well, there was this guy named Derek Parfit who seemed disturbed by my conclusion, but couldn't refute it.  The best he could do is mutter something about how the best things in his life would gradually be lost if he spent all his money on premium cable.  I'm working on him though, I think I'll be able to bring him around eventually.

Alice:  Funny you should mention Derek Parfit.  It so happens that the flaw in your "Mere Cable Channel Addition Paradox" is exactly the same as the flaw in a famous philosophical argument he made, which he called the "Mere Addition Paradox."

Bob:  Really? Do tell?

Alice:  Parfit posited a population he called "A" which had a moderately large population with large amounts of resources, giving them a very high level of utility per person.  Then he added a second population, which was totally isolated from the other population.  How they were isolated wasn't important, although Parfit suggested maybe they were on separate continents and can't sail across the ocean or something like that.  These people don't have nearly as many resources per person as the other population, so each person's level of utility is lower (their lack of resources is the only reason they have lower utility).  However, their lives are still just barely worth living.  He called the two populations "A+."

Parfit asked if "A+" was a better world than "A."  He thought it was, since the extra people were totally isolated from the original population they weren't hurting anyone over there by existing.  And their lives were worth living.  Follow me so far?

Bob: I guess I can see the point.

Alice: Next Parfit posited a population called "B," which was the same as A+. except that the two populations had merged together.  Maybe they got better at sailing across the ocean, it doesn't really matter how.  The people share their resources.  The result is that everyone in the original population had their utility lowered, while everyone in the second had it raised. 

Parfit asked if population "B" was better than "A+" and argued that it was because it had a greater level of equality and total utility.

Bob: I think I see where this is going.  He's going to keep adding more people, isn't he?

Alice:  Yep.  He kept adding more and more people until he reached population "Z," a vast population where everyone had so few resources that their lives were barely worth living.  This, he argued, was a paradox, because he argued that most people would believe that Z is far worse than A, but he had made a convincing argument that it was better.

Bob:  Are you sure that sharing their resources like that would lower the standard of living for the original population?  Wouldn't there be economies of scale and such that would allow them to provide more utility even with less resources per person?

Alice: Please don't fight the hypothetical.  We're assuming that it would for the sake of the argument.

Now, Parfit argued that this argument led to the "Repugnant Conclusion," the idea that the best sort of world is one with a large population with lives barely worth living.  That confers on people a duty to reproduce as often as possible, even if doing so would lower the quality of their and everyone else's lives.

He claimed that the reason his argument showed this was that he had conducted "mere addition."  The populations in his paradox differed in no way other than their size.  By merely adding more people he had made the world "better," even if the level of utility per person plummetted.  He claimed that "For every population, A, with a high average level of utility there exists another, better population, B, with more people and a lower average level of utility."

Do you see the flaw in Parfit's argument? 

Bob:  No, and that kind of disturbs me.  I have kids, and I agree that creating new people can add utility to the world.  But it seems to me that it's also important to enhance the utility of the people who already exist. 

Alice: That's right.  Normal morality tells us that creating new people with lives worth living and enhancing the utility of people that already exist are both good things to use resources on.  Our common sense tells us that we should spend resources on both those things.  The disturbing thing about the Mere Addition Paradox is that it seems at first glance to indicate that that's not true, that we should only devote resources to creating more people with barely worthwhile lives.  I don't agree with that, of course.

Bob:  Neither do I. It seems to me that having a large number of worthwhile lives and a high average utility are both good things and that we should try to increase them both, not just maximize one.

Alice:  You're right, of course.  But don't say "having a high average utility."  Say "use resources to increase the utility of people who already exist."

Bob:  What's the difference? They're the same thing, aren't they?

Alice:  Not quite.  There are other ways to increase average utility than enhancing the utility of existing people.  You could kill all the depressed people, for instance.  Plus, if there was a world where everyone was tortured 24 hours a day, you could increase average utility by creating some new people who are only tortured 23 hours a day.

Bob:  That's insane!  Who could possibly be that literal-minded?

Alice:  You'd be surprised.  The point is, a better way to phrase it is "use resources to increase the utility of people who already exist," not "increase average utility."  Of course, that still leaves some stuff out, like the fact that it's probably better to increase everyone's utility equally, rather than focus on just one person.  But it doesn't lead to killing depressed people, or creating slightly less tortured people in a Hellworld.

Bob:  Okay, so what I'm trying to say is that resources should be used to create people, and to improve people's lives.  Also equality is good. And that none of these things should completely eclipse the other, they're each too valuable to maximize just one.  So a society that increases all of those values should be considered more efficient at generating value than a society that just maximizes one value.  Now that we're done getting our terminology straight, will you tell me what Parfit's mistake was?

Alice:  Population "A" and population "A+" differ in two ways, not one. Think about it.  Parfit is clear that the extra people in "A+" do not harm the existing people when they are added.  That means they do not use any of the original population's resources.  So how do they manage to live lives worth living?  How are they sustaining themselves?

Bob:  They must have their own resources.  To use Parfit's example of continents separated by an ocean;  each continent must have its own set of resources.

Alice:  Exactly.  So "A+" differs from "A" both in the size of its population, and the amount of resources it has access to.  Parfit was not "merely adding" people to the population.  He was also adding resources.

Bob: Aren't you the one who is fighting the hypothetical now?

Alice:  I'm not fighting the hypothetical.  Fighting the hypothetical consists of challenging the likelihood of the thought experiment happening, or trying to take another option than the ones presented.  What I'm doing is challenging the logical coherence of the hypothetical.  One of Parfit's unspoken premises is that you need some resources to live a life worth living, so by adding more worthwhile lives he's also implicitly adding resources.  If he had just added some extra people to population A without giving them their own continent full of extra resources to live on then "A+" would be worse than "A."

Bob:  So the Mere Addition Paradox doesn't confer on us a positive obligation to have as many children as possible, because the amount of resources we have access to doesn't automatically grow with them.  I get that.  But doesn't it imply that as soon as we get some more resources we have a duty to add some more people whose lives are barely worth living?

Alice: No.  Adding lives barely worth living uses the extra resources more efficiently than leaving Parfit's second continent empty for all eternity.  But, it's not the most efficient way.  Not if you believe that creating new people and enhancing the utility of existing people are both important values. 

Let's take population "A+" again.  Now imagine that instead of having a population of people with lives barely worth living, the second continent is inhabited by a smaller population with the same very high percentage of resources and utility per person as the population of the first continent.  Call it "A++. " Would you say "A++" was better than "A+?"

Bob:  Sure, definitely. 

Alice:  How about a world where the two continents exist, but the second one was never inhabited?  The people of the first continent then discover the second one and use its resources to improve their level of utility.

Bob:  I'm less sure about that one, but I think it might be better than "A+."

Alice:  So what Parfit actually proved was: "For every population, A, with a high average level of utility there exists another, better population, B, with more people, access to more resources and a lower average level of utility."

And I can add my own corollary to that:  "For every population, B, there exists another, better population, C, that has the same access to resources as B, but a smaller population and higher average utility."

Bob: Okay, I get it.  But how does this relate to my cable TV sales pitch?

Alice:  Well, my current situation, where I'm spending my money on normal things is analogous to Parfit's population "A."  High utility, and very efficient conversion of resources into utility, but not as many resources.  We're assuming, of course, that using resources to both create new people and improve the utility of existing people is more morally efficient than doing just one or the other.

The situation where the government gives me $50 to spend on Package A+ is analogous to Parfit's population A+.  I have more resources and more utility.  But the resources aren't being converted as efficiently as they could be. 

The situation where I take the 50% discount and buy Package B is equivalent to Parfit's population B.  It's a better situation than A+, but not the most efficient way to use the money.

The situation where I get the $50 from the government to spend on whatever I want is equivalent to my population C.  A world with more access to resources than A, but more efficient conversion of resources to utility than A+ or B.

Bob: So what would a world where the government kept the money be analogous to?

Alice: A world where Parfit's second continent was never settled and remained uninhabited for all eternity, its resources never used by anyone.

Bob: I get it.  So the Mere Addition Paradox doesn't prove what Parfit thought it did?  We don't have any moral obligation to tile the universe with people whose lives are barely worth living?

Alice:  Nope, we don't.  It's more morally efficient to use a large percentage of our resources to enhance the lives of those who already exist.

Bob:  This sure has been a fun conversation.  Would you like to buy a cable package from me?  We have some great deals.

Alice: NO! 

SUMMARY:

My argument is that Parfit’s Mere Addition Paradox doesn’t prove what it seems to.  The argument behind the Mere Addition Paradox is that you can make the world a better place by the “mere addition” of extra people, even if their lives are barely worth living.  In other words : "For every population, A, with a high average level of utility there exists another, better population, B, with more people and a lower average level of utility." This supposedly leads to the Repugnant Conclusion, the belief that a world full of people whose lives are barely worth living is better than a world with a smaller population where the people lead extremely fulfilled and happy lives. 

Parfit demonstrates this by moving from world A, consisting of a population full of people with lots of resources and high average utility, and moving to world A+.  World A+ has an addition population of people who are isolated from the original population and not even aware of the other’s existence. The extra people live lives just barely worth living.  Parfit argues that A+ is a better world than A because everyone in it has lives worth living, and the additional people aren’t hurting anyone by existing because they are isolated from the original population.

Parfit them moves from World A+ to World B, where the populations are merged and share resources.  This lowers the standard of living for the original people and raises it for the newer people.  Parfit argues that B must be better than A+, because it has higher total utility and equality. He then keeps adding people until he reaches Z, a world where everyones’ lives are barely worth living and the population is vast.  He argues that this is a paradox because most people would agree that Z is not a desirable world compared to A.

I argue that the Mere Addition Paradox is a flawed argument because it does not just add people, it also adds resources.  The fact that the extra people in A+ do not harm the original people of A by existing indicates that their population must have a decent amount of resources to live on, even if it is not as many per person as the population of A.  For this reason what the Mere Addition Paradox proves is not that you can make the world better by adding extra people, but rather that you can make it better by adding extra people and resources to support them.  I use a series of choices about purchasing cable television packages to illustrate this in concrete terms.

I further argue for a theory of population ethics that values both using resources to create lives worth living, and using resources to enhance the utility of already existing people, and considers the best sort of world to be one where neither of these two values totally dominate the other.  By this ethical standard A+ might be better than A because it has more people and resources, even if the average level of utility is lower.  However, a world with the same amount of resources as A+, but a lower population and the same, or higher average utility as A is better than A+.

The main unsatisfying thing about my argument is that while it avoids the Repugnant Conclusion in most cases, it might still lead to it, or something close to it, in situations where creating new people and getting new resources are, as one commenter noted, a “package deal.”   In other words, a situation where it is impossible to obtain new resources without creating some new people whose utility levels are below average.  However, even in this case, my argument holds that the best world of all is one where it would be possible to obtain the resources without creating new people, or creating a smaller amount of people with higher utility.

In other words, the Mere Addition Paradox does not prove that: "For every population, A, with a high average level of utility there exists another, better population, B, with more people and a lower average level of utility." Instead what the Mere Addition Paradox seems to demonstrate is that: "For every population, A, with a high average level of utility there exists another, better population, B, with more people, access to more resources and a lower average level of utility."  Furthermore, my own argument demonstrates that: "For every population, B, there exists another, better population, C, which has the same access to resources as B, but a smaller population and higher average utility."

[LINK] Anchoring Bias In Medicine (NYT)

4 [deleted] 20 July 2012 03:31AM

http://well.blogs.nytimes.com/2012/07/19/falling-into-the-diagnostic-trap/

For the doctors, this was a harrowing lesson in the trap of anchoring bias. It is so easy to slip into it without even knowing. But this case reminded us to keep reciting the mantra: if something doesn’t fit, don’t try to make it fit. Ask what else might be going on. Don’t fall into the trap.

(Wikipedia's article: http://en.wikipedia.org/wiki/Anchoring )

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