Should You Trust “Experts”?

The sometimes perceptive, sometimes bizarre, but usually interesting Eliezer Yudkowsky has a new set of posts up at, excerpts from his book Inadequate Equilibria. ( is the successor site, established in 2017, to the rationalist site Less Wrong.) The first post of interest is

Inadequacy and Modesty.

Yudkowsky has two main topics: One is when to trust one’s own judgment, when one disagrees with experts, versus going with the experts’ opinion. The link above talks about informationally efficient and inefficient situations, where we can roughly define an informationally efficient situation as one where the experts are as right as possible given currently available information.

His second topic is the set of ways that a society can get stuck in a suboptimal equilibrium. That’s an enormous topic, which I’ll take up in a later post, but the connection is this: One example of such suboptimality is when there are insufficient incentives for the discovery and spread of information. The dissemination of information – who knows what – is obviously connected to the topic of expertise.

For me, there are two main items of interest in all this. One is random walks and their links to rational beliefs, and the other is the question of expertise itself.

A random walk is a kind of variable that often arises in informationally efficient situations. Yudkowsky uses the classic exanple of stock prices, though he doesn’t use the term “random walk.” He discusses the reasons to believe that stock markets are informationally efficient, which means that all relevant information known to market participants is already incorporated into stock prices. That in turn implies that you can’t profit by second-guessing the market, because the expected (i.e., mean) change in the price is zero. That in turn is the definition of a random walk. (If you’ve ever taken a Finance class this may sound familiar; it’s the Efficient Markets Hypothesis.)

See my post The Mind Cannot Foresee its Own Advance, which presents a generalization of this point.

There are good reasons to think that stock markets are pretty damn informationally efficient:

Empirically, it’s extremely difficult to beat the market – for periods of time long enough to not just be temporary luck – even with Cray big iron and a truckload of quant PhDs on staff. This empirical regularity is the real meat of the argument. But why is that the case? Several reasons, noted by Yudkowsky (but my wording here):

1. There are enormous incentives $$$!!! to uncover patterns that other market participants haven’t uncovered, so you can second-guess them and make bug bucks,

2. There are lots of people involved in attempting to do this constantly, which tends to push securities prices in the correct direction,(*)

(*) If a security is underpriced you should buy it to profit when people eventually realize it’s underpriced and the price rises. But also, the very fact of your buying it constitutes an increase in demand for it, which tends to push the price up. A symmetric phenomenon happens when you bet on a price falling in the future.

3. There is fast feedback from empirical reality telling them whether their trading strategies are successful, so fast error correction,

4. You can bet either way in the stock markets. That means that whether everybody else is too optimistic or too pessimistic, there are bets you can place to profit when the current mispricing is eventually corrected.

At the link above Yudkowsky says, somewhat floridly,

In the thickly traded parts of the stock market, where the collective power of human civilization is truly at its strongest, I doff my hat, I put aside my pride and kneel in true humility to accept the market’s beliefs as though they were my own, knowing that any impulse I feel to second-guess and every independent thought I have to argue otherwise is nothing but my own folly. If my perceptions suggest an exploitable opportunity, then my perceptions are far more likely mistaken than the markets. That is what it feels like to look upon a civilization doing something adequately.

A very important point here is that stock markets are exceptional! As points 1 – 4 explain, there are reasons to think the experts – in this case, securities trading firms – are correct on average.

But in the generic case – consider the field of history, e.g. – none of those things is true. And the whole question of who is an expert basically scuttles this attempt to say “You should often defer to experts.”

For example, Marxist historians like to say that they’re experts on history – they’ve figured out its ineluctable laws! – but they’re actually a bunch of ideological fuckwits who can’t think themselves out of a paper bag. But they’re also professors at many a US university (all the universities, I think). They’ll tell you they’re experts, man. It says so right here on the label, “I’m an expert.”

So is that a reason to regard them as experts?

Plainly not. Well, but we don’t have to trust them on this; after all, they’re hired by universities! Universities must be unbiased; it says so right on the label! Right? No, actually universities (outside of STEM fields, and increasingly even there) are also largely a bunch of ideological fuckwits.

Or so I claim. Am I right or wrong? Before you respond, I claim that I’m an expert on this topic. Hmmmm, we’d need to assess their degree of ideological fuckwittery empirically, wouldn’t we?

Or are we going to count heads? Whose heads? The historians’? But they’re the ones whose very credibility is being questioned, so that would be going in a circle.

How about the average person? Well, the Marxists lose that one, since most people aren’t Marxists. More to the point, if we’re asking people other than soi-disant “experts,” we’ve already departed from the dictum “trust experts.”

(By the way, should we trust the pollsters who are doing the head counting? Are their polling methods unbiased? Are they competent polling experts? How do you know?)

Furthermore, there are no particular incentives to be correct in this area. Your fellow historians are largely leftists who will grant you tenure for saying, in various ways, “Socialism is nice. Capitalism is bad.” You are not betting your own money or your life by predicting that next time – in China… Cuba… Venezuela! – socialism is sure to work.

Marxism is not intended to factually describe reality anyway. It’s an ideology of power, a convenient pre-made language for people who want to seize power, and realize they need a veneer of justice to help them gain adherents, put their opposition on the defensive, etc. Or as Marx himself put it, more discreetly: “The philosophers have only interpreted the world, in various ways. The point, however, is to change it.”

Once it’s recognized that you can’t just trust anyone who says “I’m an expert” – anyone can say that – the whole epistemic question returns to the forefront. How are you going to judge who’s an expert? Hmmm, maybe we need some standards regarding the use of evidence. (Frequentist? Bayesian?) Also some procedures, like whether testable empirical claims are being made, whether they’re replicable and actually replicated, etc.

You see the problem: In order to judge who’s an expert, you have to be damn far along the trajectory of knowledge in the relevant subject, far enough along that you’d be a jack-leg expert yourself on the topic. You might as well just assess the evidence for yourself, ignoring the purported “experts.”

What I do, and I hope everyone does, is try to identify areas in which there don’t seem to be monetary or ideological incentives to be biased, and provisionally trust the experts in those areas, and ignore experts in areas where the incentives are bad. This is far from foolproof, of course. (I’m perpetually surprised by how politicized nutrition science is.) But given the impossibility of becoming experts ourselves in all topics, we use heuristics, imperfect though they are, to try to avoid getting scammed by fraudulent “experts.”

There are many reasons, not just malign intent, that this instinct to mistrust “experts” is sound. Yudkowsky mentions some and I will mention others in my next post.

Here’s a teaser: In my next post I will cite a paper by two game theorists on the topic of expertise. This paper was published in The Quarterly Journal of Economics, which is a top Economics journal in the world. A major conclusion of the paper: In general, the equilibrium outcome is that experts will deliberately not inform you perfectly. Now here’s my question for anyone who says “trust experts”: Do you trust the conclusion of these two game theory experts?


Slate Star Codex on Creationism and the Outside View

Scott Alexander at the Slate Star Codex blog has reviewed Inadequate Equilibria by Eliezer Yudkowsky. I’ve read substantial excerpts from the book (on the new Less Wrong site,, and the book will be interesting to anyone interested in epistemology and/or game theory, in particular, Pareto-suboptimal Nash Equilibria and how to escape them. More about that in future posts.

One of the topics in SSC’s review is epistemology, particularly how evolutionists (that includes me) can judge that their belief in evolution is better-founded than creationists’ belief in creationism. SSC grapples (as does the book) with something called the Outside View. Briefly, this is when you try to look at your judgments as if you were an objective third party, from a distance. E.g., you may think you’re a better-than-average driver, but apparently most people do, so maybe you’re just biased. After all, it’s a fact that a significant proportion of people who think they’re better-than-average drivers are wrong. Maybe you’re one of them.

But if you think in terms of the outside view you can get yourself all knotted up. SSC goes off the rails here:

I believe in evolution. But about half of Americans believe in creation. So either way, half of people are wrong about the evolution-creation debate. Since I know I’m in a category, half of whom are wrong, I should assume there’s a 50-50 chance I’m wrong about evolution.

SSC admits this is a “pathological” application of the Outside View. Yes, it is, but why? Because there has been no evidence put forward.

But surely the situation isn’t symmetrical? After all, the evolution side includes all the best biologists, all the most educated people, all the people with the highest IQ. The problem is, the true Outside Viewer can say “Ah, yes, but a creationist would say that their side is better, because it includes all the best fundamentalist preachers, all the world’s most pious people, and all the people with the most exhaustive knowledge of Genesis. So you’re in a group of people, the Group Who Believe That Their Side Is Better Qualified To Judge The Evolution-Creation Debate, and 50% of the people in that group are wrong. So this doesn’t break the fundamental symmetry of the situation.

But fundamentalist preachers and pious people are not evidence about the world, nor is Genesis. Evolution is about the world. Any given book may or may not be about the world. What is evidence about the world? The world! This is really just obvious. Now I guess someone could respond with, “Oooooh, no it’s not!” But note that kind of rejection of evidence rejects everything. If I can’t trust what my eyes tell me about the world, then I can’t trust what they tell me the words are in the Bible, either. I also can’t trust them when they tell me that this dude has a degree in Theology hanging on his wall. And I can’t trust my ears when creationists tell me, “All the most pious Genesis scholars are on our side,” etc. See, the fantastic thing about bullshit is that if you push it hard enough, it destroys itself.

SSC mentions a true psychological case study known as the Three Christs Of Ypsilanti, in which three men in a mental hospital all thought they were Jesus:

…imagine that when Schizophrenic A was confronted with the other Christs, he protested that he had special evidence it was truly him. In particular, the Archangel Gabriel had spoken to him and told him he was Jesus. Meanwhile, Schizophrenic B had seen a vision where the Holy Spirit descended into him in the form of a dove. Schizophrenic A laughs. “Anyone can hallucinate a dove. But archangels are perfectly trustworthy.” Schizophrenic B scoffs. “Hearing voices is a common schizophrenic symptom, but I actually saw the Spirit”. Clearly they still are not doing Outside View right.

But if you can’t trust your senses, you can’t trust anything. This gets us to radical skepticism a la Rene Descartes and David Hume, etc. See above remarks on pious Genesis scholars, etc. (Note: Phil Collins was their drummer. Har!)

And in particular, if you can’t trust your senses, you have no reason to believe that there are two other people hanging around near you who also think they’re Jesus. So you have no need to engage with the intellectual problem they pose. There is no intellectual problem they pose.

(I’ve included more on the Three Christs Of Ypsilanti at the end of this post.)

So overall, when SSC worries,

…half of people are wrong about the evolution-creation debate. Since I know I’m in a category, half of whom are wrong, I should assume there’s a 50-50 chance I’m wrong about evolution

…he’s fretting for no reason. Creationists have basically no evidence on their side. If they really are saying “People who are pious accept creationism” as evidence for creationism – I’ve never heard that one before – just point out that a person’s adherence to a religion has nothing to do with the soundness of their judgments about the factual topic of evolution. Things like junk DNA, the blind spot in the human eye, and bacteria developing antibiotic resistance are relevant evidence. Creationists’ opinions about these things are not evidence. Evolutionists’ opinions aren’t evidence either. Why even discuss people’s opinions as if they’re evidence?

It’s as if SSC is saying, “I am wearing a green sweater. But there’s a creationist wearing a green sweater too. So either way, half of all the people wearing green sweaters are wrong about creationism vs. evolution!” Um… what? This isn’t even a thing. And it’s just as relevant as saying, “A lot of creationists feel subjectively certain about creationism, just as I feel subjectively certain about evolution. So there’s a 50% chance that I’m wrong!” Dude, NO. Your evidence for evolution is not that you feel pretty certain about it. Your evidence is the fossil record, etc.

Indeed, this totally puts the cart before the horse. We feel pretty certain about evolution because of the evidence for it. The feeling of near-certainty is not itself the evidence!

In this sense, I think the Ypsilanti Jesus example, where all the evidence is “I just know,” really has drawn people off on a tangent about the outside view. It’s an unfortunate side detour, that has wasted the time of people like SSC and not really produced much else, other than that one semi-amusing blog post on LiveJournal.

More on the Three Christs Of Ypsilanti:

Another SSC quote:

The Three Christs Of Ypsilanti is a story about three schizophrenics who thought they were Jesus all ending up on the same psych ward. Each schizophrenic agreed that the other two were obviously delusional. But none of them could take the next step and agree they were delusional too… They should have said “At least 66% of people in this psych hospital who believe they’re Jesus are delusional. This suggests there’s a strong bias, like a psychotic illness, that pushes people to think they’re Jesus. I have no more or less evidence for my Jesus-ness than those people, so I should discount my apparent evidence – my strong feeling that I am Him – and go back to my prior that almost nobody is Jesus.”

Note it’s important that each one’s “evidence” for his being Jesus was entirely a mystic feeling that he was Jesus. But that’s not evidence. More on that in a second.

SSC also links to this sorta famous (in rationalist circles) piece about Jesus, which I linked to above:

The idea, if you don’t want to click through, is that Satan doesn’t bother trying to tempt Jesus with worldly power or whatever. He just says, “Look, dude, of all the people who think they’re Jesus, what are the odds that you’re actually Him?” I don’t buy this argument, because the entire assumption is that Jesus has some divine epistemological uber-magic that is a source of complete certainty. But anyway, in the story Jesus doesn’t fall for it; he just pushes Satan off a cliff. LOL. (Also, Jesus could simply work a miracle – say, levitating a mountain or whatever – to reassure Himself that he’s Him, granting the weird assumption that He’d need to re-assure Himself. And how could there be thousands of dudes thinking they’re Jesus while Jesus’s life is still going on? He has to enter the historical record first. Satan claims he’s showing Jesus the future, but why believe the Father of Lies? All right, whatever, getting off topic.) The point is, whatever you think of this story, a fundamental point within it is that Jesus’s only evidence for being Jesus is that he feels subjectively certain that he is. That’s also the case for the Three Christs of Ypsilanti; it is fundamental to both that the only evidence for Jesus-ness is “I have a special feeling.”

But DUDE. Our evidence for evolution is not that we have a special feeling about it. It’s the fossil record, etc., etc., etc.

If the rumors are true, Donny, you just lost 2020

Donald, the American people elected you to do one job:

Hold the line on immigration.

Obviously that means no amnesty.

Not under any conditions.

There are other things that are important, but not that important.

So if what we’re hearing, that you’re supporting an amnesty, is true, you just sold out the American nation and made a civil war, of the literal variety, inevitable.

You also, if you care, just lost 2020.

(You also just destroyed your ability to portray yourself as a good negotiator. When the opposition opens with “We demand amnesty for 800,000 illegal invaders!” and your response is “Oh yeah? How about 1.8 million!?” you’re being ass-raped at the negotiating table.

By Chuck Schumer.)

The only shred of hope I see here is that the media, being liars, have done their usual “Let’s just lie!” and portrayed you as supporting something you don’t support.