The character of the new site is becoming clear.  The pace of commenting is higher; the threaded comments encourage short replies and continuing conversations.  The pace of posting exceeds my fondest hopes – apparently not being able to post automatically on OB was a much greater barrier to potential contributors than I realized.

We've had 12,428 comments so far on 113 articles, 100 of them posted since contributing was enabled for all users over 20 karma on March 5th.

Browsing to the Top Scoring articles on Less Wrong will give you an idea of how things are developing.  A quick view of all posts can be found here, with the current top scorer being "Cached Selves" by Salamon and Rayhawk, followed by "Rational Me or We?" by Hanson.  If this looks like a blog you like, go ahead and add it to your blog roll now, please!

• Yvain has emerged as a prolific and highly upvoted contributor with too many excellent posts to mention, but The Apologist and the Revolutionary (on brain damage and rationalization) and The Least Convenient Possible World (an exercise in not avoiding painful questions) are two places to start.
• Our most highly commented thread was And's Closet survey #1:  What do you believe that most people on this site don't? with 314 comments.
• Johnicholas brings us Information Cascades showing how taking other people's ratings into account in your own vote vastly decreases the information content…
• …which inspired Marcello to build the anti-kibitzer Firefox extension that hides comment authors and vote counts.  (We'd like to integrate these sorts of features into the site, but we need more Python programmers!)
• Alicorn observes that systems of rationality must have two tiers: an ideal tier, and a tier that can actually be implemented (analyzing consequentialism as an example).
• Kaj_Sotala asks whether blind review slows down science by preventing old scientists from championing new ideas.
• MBlume asks what resources are available for raising young rationalists.
• Jimrandomh notes that support can sound like dissent, creating a false picture of the overall reaction, and suggests prefixing "I agree with your conclusion, but…"

• Steven0461 on "The Wrath of Kahneman"
• Z_M_Davis on "It's the Same Five Dollars!"
• Vladimir_Nesov on "Counterfactual Mugging"
• Thomblake on "Is Santa Real?"
• Phil Goetz on "Soulless Morality"
• Carl Shulman warns us, "Don't Revere The Bearer of Good Info"
• Patri Friedman on "Individual Rationality is a Matter of Life and Death"
• …and the list goes on.  And any number of highly intelligent comments are being upvoted to the prominence they deserve.

It might be just my imagination or my prior hopes, but it looks to me like the threaded, rated, and sorted comments create a completely different experience of reading a post – the first comment you encounter is going to be something highly intelligent, and then right away, you're going to see the most intelligent reply and a well-sorted discussion all in one place.  Much more of the action is in the comments.

The karma system is giving me valuable (if not always pleasant) feedback about which of my posts and comments my readers actually like.  I shall try not to be too influenced by this.

An on-site wiki is on the way, and meanwhile there's a temporary Wiki hosted at Wikia, currently with 163 articles.

Though it's an easy enough signal to fake, I find it noteworthy that Moyo – in this interview at least – repeatedly pleads for some attention to "logic and evidence":

"I think the whole aid model is couched in pity.  I don’t want to cast aspersions as to where that pity comes from.  But I do think it’s based on pity because based on logic and evidence, it is very clear that aid does not work.  And yet if you speak to some of the biggest supporters of aid, whether they are academics or policy makers or celebrities, their whole rationale for giving more aid to Africa is not couched in logic or evidence; it’s based largely on emotion and pity."

I was just trying to think of when was the last time I heard a Western politician – or even a mainstream Western economist in any public venue – draw an outright battle line between logic and pity.  Oh, there are plenty of demagogues who claim the evidence is on their side, but they won't be so outright condemning of emotion – it's not a winning tactic.  Even I avoid drawing a battle line so stark.

Moyo says she's gotten a better reception in Africa than in the West.  Maybe you need to see your whole continent wrecked by emotion and pity before "logic and evidence" start to sound appealing.

This site is missing some features, but it looks to me like a starting attempt at what's needed – a Wikipedia-like, user-contributed, low-barrier-to-entry database of all pundit predictions, past and present.

So I observed that:

1. Although the laws of physics as we know them don't allow any agent to survive for infinite subjective time (do an unboundedly long sequence of computations), it's possible that our model of physics is mistaken.  (I go into some detail on this possibility below the cutoff.)
2. If it is possible for an agent – or, say, the human species – to have an infinite future, and you cut yourself off from that infinite future and end up stuck in a future that is merely very large, this one mistake outweighs all the finite mistakes you made over the course of your existence.

And the one said, "Isn't that a form of Pascal's Wager?"

I'm going to call this the Pascal's Wager Fallacy Fallacy.

You see it all the time in discussion of cryonics.  The one says, "If cryonics works, then the payoff could be, say, at least a thousand additional years of life."  And the other one says, "Isn't that a form of Pascal's Wager?"

The original problem with Pascal's Wager is not that the purported payoff is large.  This is not where the flaw in the reasoning comes from.  That is not the problematic step.  The problem with Pascal's original Wager is that the probability is exponentially tiny (in the complexity of the Christian God) and that equally large tiny probabilities offer opposite payoffs for the same action (the Muslim God will damn you for believing in the Christian God).

However, what we have here is the term "Pascal's Wager" being applied solely because the payoff being considered is large – the reasoning being perceptually recognized as an instance of "the Pascal's Wager fallacy" as soon as someone mentions a big payoff – without any attention being given to whether the probabilities are in fact small or whether counterbalancing anti-payoffs exist.

And then, once the reasoning is perceptually recognized as an instance of "the Pascal's Wager fallacy", the other characteristics of the fallacy are automatically inferred: they assume that the probability is tiny and that the scenario has no specific support apart from the payoff.

But infinite physics and cryonics are both possibilities that, leaving their payoffs entirely aside, get significant chunks of probability mass purely on merit.

Yet instead we have reasoning that runs like this:

1. Cryonics has a large payoff;
2. Therefore, the argument carries even if the probability is tiny;
3. Therefore, the probability is tiny;
4. Therefore, why bother thinking about it?

(Posted here instead of Less Wrong, at least for now, because of the Hanson/Cowen debate on cryonics.)

Further details:

Pascal's Wager is actually a serious problem for those of us who want to use Kolmogorov complexity as an Occam prior, because the size of even the finite computations blows up much faster than their probability diminishes (see here).

See Bostrom on infinite ethics for how much worse things get if you allow non-halting Turing machines.

In our current model of physics, time is infinite, and so the collection of real things is infinite.  Each time state has a successor state, and there's no particular assertion that time returns to the starting point.  Considering time's continuity just makes it worse – now we have an uncountable set of real things!

But current physics also says that any finite amount of matter can only do a finite amount of computation, and the universe is expanding too fast for us to collect an infinite amount of matter.  We cannot, on the face of things, expect to think an unboundedly long sequence of thoughts.

The laws of physics cannot be easily modified to permit immortality: lightspeed limits and an expanding universe and holographic limits on quantum entanglement and so on all make it inconvenient to say the least.

On the other hand, many computationally simple laws of physics, like the laws of Conway's Life, permit indefinitely running Turing machines to be encoded.  So we can't say that it requires a complex miracle for us to confront the prospect of unboundedly long-lived, unboundedly large civilizations.  Just there being a lot more to discover about physics – say, one more discovery of the size of quantum mechanics or Special Relativity – might be enough to knock (our model of) physics out of the region that corresponds to "You can only run boundedly large Turing machines".

So while we have no particular reason to expect physics to allow unbounded computation, it's not a small, special, unjustifiably singled-out possibility like the Christian God; it's a large region of what various possible physical laws will allow.

And cryonics, of course, is the default extrapolation from known neuroscience: if memories are stored the way we now think, and cryonics organizations are not disturbed by any particular catastrophe, and technology goes on advancing toward the physical limits, then it is possible to revive a cryonics patient (and yes you are the same person).  There are negative possibilities (woken up in dystopia and not allowed to die) but they are exotic, not having equal probability weight to counterbalance the positive possibilities.

For those of you who haven't yet subscribed to / gotten in the habit of checking Less Wrong:

• Test Your Rationality by Robin Hanson.  It's easy to find reasons to believe yourself more rational than others, but most people do this; what real ways can be found to test your rationality?
• Unteachable Excellence and Teaching the Unteachable by Eliezer Yudkowsky.  The rare superstars are rare because their skills are currently hard to transfer.  A large number of Nobel laureates are students of other Nobel laureates.  How do you teach skills you can't put into words?
• The Costs of Rationality by Robin Hanson.  Rationality can be useful for many things, but humans aren't really designed for it, and a true effort to believe truly can get in the way of many aspects of ordinary life.  Are you willing to pay the real costs of ratonality?
• No, Really, I've Deceived Myself and Belief in Self-Deception by Eliezer Yudkowsky.  A woman I met who didn't seem to believe in God at all, while honestly believing that she had deceived herself successfully – which may bring most of the same placebo benefits.
• The ethic of hand-washing and commuity epistemic practice by Steve Rayhawk and Anna Salamon.  Diseases become more virulent in the presence of poor hygiene, since they can jump hosts more easily.  Are there analogous effects for ideas?  What is the equivalent of washing our hands?

The five most recent LW posts now appear in OB's sidebar (and vice versa), but aside from this you shouldn't expect further regular summaries of LW on OB.

Continue reading "The Most Frequently Useful Thing" at Less Wrong »

So let me ask – what was the one thing you learned from my posts on Overcoming Bias, that stands out as most important in your mind?

Continue reading "The Most Important Thing You Learned" at Less Wrong »

Posting by non-admins is disabled for now – today we're just testing out registration, commenting, threading, etcetera.)

To break up the awkward silence at the start of a recent Overcoming Bias meetup, I asked everyone present to tell their rationalist origin story – a key event or fact that played a role in their becoming rationalists.  This worked surprisingly well.

There is, I think, a second Pons Asinorum associated with more advanced finance, and it is the concept that markets are an anti-inductive environment.

Let's say you see me flipping a coin.  It is not necessarily a fair coin.  It's a biased coin, and you don't know the bias.  I flip the coin nine times, and the coin comes up "heads" each time.  I flip the coin a tenth time.  What is the probability that it comes up heads?

If you answered "ten-elevenths, by Laplace's Rule of Succession", you are a fine scientist in ordinary environments, but you will lose money in finance.

In finance the correct reply is, "Well… if everyone else also saw the coin coming up heads… then by now the odds are probably back to fifty-fifty."

Recently on Hacker News I saw a commenter insisting that stock prices had nowhere to go but down, because the economy was in such awful shape.  If stock prices have nowhere to go but down, and everyone knows it, then trades won't clear – remember, for every seller there must be a buyer – until prices have gone down far enough that there is once again a possibility of prices going up.

So you can see the bizarreness of someone saying, "Real estate prices have gone up by 10% a year for the last N years, and we've never seen a drop."  This treats the market like it was the mass of an electron or something.  Markets are anti-inductive.  If, historically, real estate prices have always gone up, they will keep rising until they can go down.

To get an excess return – a return that pays premium interest over the going rate for that level of riskiness – you need to know something that other market participants don't, or they will rush in and bid up whatever you're buying (or bid down whatever you're selling) until the returns match prevailing rates.

If the economy is awful and everyone knows it, no one's going to buy at a price that doesn't take into account that knowledge.

If there's an obvious possibility of prices dropping further, then the market must also believe there's a probability of prices rising to make up for it, or the trades won't clear.

This elementary point has all sorts of caveats I'm not bothering to include here, like the fact that "up" and "down" is relative to the risk-free interest rate and so on.  Nobody believes the market is really "efficient", and recent events suggest it is less efficient than previously believed, and I have a certain friend who says it's even less efficient than that… but still, the market does not leave hundred-dollar-bills on the table if everyone believes in them.

There was a time when the Dow systematically tended to drop on Friday and rise on Monday, and once this was noticed and published, the effect went away.

Past history, e.g. "real estate prices have always gone up", is not private info.

And the same also goes for more complicated regularities.  Let's say two stock prices are historically anticorrelated – the variance in their returns moves in opposite directions.  As soon as everyone believes this, hedge-fund managers will leverage up and buy both stocks.  Everyone will do this, meaning that both stocks will rise.  As the stocks rise, their returns get more expensive.  The hedge-fund managers book profits, though, because their stocks are rising.  Eventually the stock prices rise to the point they can go down.  Once they do, hedge-fund managers who got in late will have to liquidate some of their assets to cover margin calls.  This means that both stock prices will go down – at the same time, even though they were originally anticorrelated.  Other hedge funds may lose money on the same two stocks and also sell or liquidate, driving the price down further, etcetera.  The correlative structure behaves anti-inductively, because other people can observe it too.

If mortage defaults are historically uncorrelated, so that you can get an excess return on risk by buying lots of mortages and pooling them together, then people will rush in and buy lots of mortgages until (a) rates on mortgages are bid down (b) individual mortgage failure rates rise (c) mortgage failure rates become more correlated, possibly looking uncorrelated in the short-term but having more future scenarios where they all fail at once.

Whatever is believed in, stops being real.  The market is literally anti-inductive rather than anti-regular – it's the regularity that enough participants induce, which therefore goes away.

This, as I understand it, is the standard theory of "efficient markets", which should perhaps have been called "inexploitable markets" or "markets that are not easy to exploit because others are already trying to exploit them".  Should I have made a mistake thereof, let me be corrected.

Now it's not surprising, on the one hand, to see this screwed up in random internet discussions where a gold bug argues from well-known observations about the past history of gold.  (This is the equivalent of trying to make money at horse-racing by betting on the horse that you think will win – failing to cross the Pons Asinorum.)

But it is surprising is to hear histories of the financial crisis in which prestigious actors argued in crowded auditoriums that, previously, real-estate prices had always gone up, or that previously mortage defaults had been uncorrelated.  This is naive inductive reasoning of the sort that only works on falling apples and rising suns and human behavior and everything else in the universe except markets.  Shouldn't everyone have frowned and said, "But isn't the marketplace an anti-inductive environment?"

Not that this is standard terminology – but perhaps "efficient market" doesn't convey quite the same warning as "anti-inductive".  We would appear to need stronger warnings.

PS:  To clarify, the coin example is a humorous exaggeration of what the world would be like if most physical systems behaved the same way as market price movements, illustrating the point, "An exploitable pricing regularity that is easily inducted degrades into inexploitable noise."  Here the coin coming up "heads" is analogous to getting an above-market return on a publicly traded asset.

Looking down on others is fun, and if there's one group we adults can all enjoy looking down on, it's children.  At least I assume this is one of the driving forces behind the incredible disregard for… but don't get me started.

Inconveniently, though, most of us were children at one point or another during our lives.  Furthermore, many of us, as adults, still believe or choose certain things that we happened to believe or choose as children.  This fact is incongruent with the general fun of condescension – it means that your life is being run by a child, even if that particular child happens to be your own past self.

I suspect that most of us therefore underestimate the degree to which our youths were formative – because to admit that your youth was formative is to admit that the course of your life was not all steered by Incredibly Deep Wisdom and uncaused free will.

To give a concrete example, suppose you asked me, "Eliezer, where does your altruism originally come from?  What was the very first step in the chain that made you amenable to helping others?"

Then my best guess would be "Watching He-Man and similar TV shows as a very young and impressionable child, then failing to compartmentalize the way my contemporaries did."  (Same reason my Jewish education didn't take; I either genuinely believed something, or didn't believe it at all.  (Not that I'm saying that I believed He-Man was fact; just that the altruistic behavior I picked up wasn't compartmentalized off into some safely harmless area of my brain, then or later.))

It's my understanding that most people would be reluctant to admit this sort of historical fact, because it makes them sound childish – in the sense that they're still being governed by the causal history of a child.

But I find myself skeptical that others are governed by their childhood causal histories so much less than myself – especially when there's a simple alternative explanation: they're too embarrassed to admit it.

A lovely excuse, of course, is that we at first ended up in a certain place for childish reasons, and then we went back and redid the calculations as adults, and what do you know, it magically ended up with the same bottom line.

Well – of course that can happen.  If you ask me why I'm out to save the world, then there's a sense in which I can defend that as a sober utilitarian calculation, "Shut up and multiply", that has nothing to do with spending my childhood reading science fiction about protagonists who saved the world.  But if you ask me why I listen to that sober utilitarian calculation, why it actually has the capacity to move me – then yes, the fact that the first "grownup" book I read was Dragonflight may have played a role.  It's what F'lar and Lessa would do.

Why not really start over from scratch – throw away our childhoods and redo everything?

For epistemic beliefs that might be sorta-possible, which is why I didn't name an epistemic belief that I think I inherited from the chaos of childhood.  That wouldn't be tolerable, and when I look back, I really have rejected a lot of what I once believed epistemically.

But matters of taste?  Of personality?  Of deeply held ideals and values?

Well, yes, I reformulated my whole metaethics at a certain point and that had a definite influence on my values… but despite that, I think you could draw an obvious line back from where I am now, to factors like reading Dragonlance at age nine and vowing never to end up like Raistlin Majere.  (Bitter genius archetype.)

If you can't look back and draw a line between your current adult self and factors like that, I have to wonder if your self-history is really accurate.

In particular, I have to wonder if you're thinking right now of a deceptively obvious-seeming line that someone else might be tempted to draw, but which of course isn't the real reason why you still…

PS:  Of course I don't directly justify any of my decisions, these days, by saying "That's what the Thundercats did, therefore it is right."  The question is more like whether I ended up finding developed altruistic philosophies more appealing as an adult because, sometime back in my youth, I was bombarded with altruistic messages.

If there are many different stores selling developed philosophies, then which store you walk into to buy your sophisticated adult judgments might depend on a factor like that.

PPS:  Several commenters asked why I focused on fiction.  I could point to several real-life events in my childhood that I still remember and that seem promisingly characteristic of "me" – for example, the only time I remember my kindergarten classmates ever praising me or liking me was the time I used wooden blocks to build a complicated track that they could "ski" along.  Making something clever = peer approval, says this memory.

But because this was a one-off event, I doubt it would have quite as much influence as messages repeated over and over, through many different TV shows with similar themes, or many different books written by science-fiction authors who influenced one another.  I couldn't recite the plot of even a single episode of He-Man, but I have some memory of what the opening theme song was, because it was recurring.  That's the power of a fictional corpus, relative to any single moment of real life no matter how significant it seems – fictions can repeat the same message over and over.

My childhood universe was very much a universe of books.  The nonfiction I read (like the Childcraft books) might have been formative in a sense – but factual beliefs you really can recheck and redo.  Hence my citation of fiction as a lingering influence on values and personality.