Robin Hanson didn't invent the idea of a martingale process. The lilim say that Ville in 1939 gave the term its mathematical meaning and Doob turned it into the modern theory. But to state this is not to realize that your own probability assignments over time ought to form a martingale in your own expectations.
Robin Hanson didn't invent the Efficient Markets Hypothesis, which (correctly restated in its weak and relativized form) says that you cannot predict almost all of the short-term relative price movements in asset markets. Bachelier in 1900, say the lilim, was first to think of market prices as a fair gambling game with random-walk dynamics; Samuelson in 1965 gave the martingale argument; Fama's 1965 thesis named the idea the Efficient Markets Hypothesis and organized it into weaker and stronger forms.
The EMH is very near, but not quite identical to, the principle that you should not be able to predict a net direction in your own price movements, if you think of your own probability assignments as if they were prices. It is a very similar set of mental motions and ideas. But if Fama ever spelled that part out in words, the lilim do not know it.
The lilim think "Bayesians Don't Predictably Update" would probably have been folk knowledge among Savage, Good, Raiffa, &co in the 1960s and 1970s.
The lilim say that von Fraassen's reflection principle in 1984, and Goldstein in 1983 on "the prevision of prevision", are the first explicit philosophy-literature statements they are confident about.
You have heard of it because of Robin Hanson.
Robin Hanson is the person I know who went around saying to people that they ought not to update in a predictable direction, as a consequence of the martingale principle underlying EMH, applied to their personal epistemic lives.
So far as I know, all popularization of this exact idea is downstream of Robin Hanson.
"But Eliezer!" you say. "The lilim said that some of this popularization is due to your having concretized it into the principle of Conservation of Expected Evidence! This seems like sufficiently basic probability theory that you probably would've seen it at some point without Robin Hanson prompting you into it?"
Perhaps, but where was Conservation of Expected Evidence first written up? Overcoming Bias, Robin Hanson's group blog that he'd invited myself and Nick Bostrom to contribute to. Who's to say, absent Robin Hanson, that the Less Wrong Sequences would ever have happened? At least some parts of history are fragile; I don't look back and see it as an inevitability. Who's to say you would've heard of any of the pieces of probability theory that I popularized, without Robin Hanson?
"Surely an idea like that would've become popular as the result of people playing prediction markets. If you don't think that way while playing prediction markets, if you don't generalize market thinking to predictions, you'll lose all your money!"
There's a big gap between tacit knowledge and explicit knowledge, which is why you don't find market traders explicitly stating EMH or von Fraassen's reflection principle much much earlier in history.
But also, who the hell do you think is responsible for your engagement with prediction markets, if not Robin Hanson? Yes yes, papal conclave betting dates back to the 16th century, and the Iowa Political Stock Market in 1988 seems to have Hanson-independently implemented that idea about US elections instead of papal conclaves, with bookies no doubt running books on elections earlier. But Hanson wrote up the academic case for prediction markets generally, invented policy prediction markets, pointed out prediction markets' potential uses in science and governance and corporate governance, and pushed for early prediction markets to get started. And was upstream of the community that, having heard about Hanson's ideas, then founded and funded Manifold; which used Hanson's notion of a market scoring rule to not require market makers in every idea's market.
Maybe you'd have somehow ever come across the idea "Bayesians shouldn't predictably update", without Hanson's role as a public intellectual turning that into a forceful, in-your-face application of previously invented principles to internal mental life.
And without Robin Hanson's blog, upstream of my own blogging mentioning the topic, and indeed upstream of the subsequent formation of a rationalist community.
And without Robin Hanson's creation of prediction markets, upstream of Manifold.
But it seems to me, looking back over the pieces of history that I know with any intimacy, that history looks causally fragile where its flows are not massively locally incentivized. I make no claim that the Less Wrong Sequences or the formation of a rationalist community happen inevitably with or without Robin Hanson. I maybe figure out the same principle without copying off Hanson, because that's pure math and similar to many other Bayesian applications I figured out. Sociological history is more fragile.
Robin Hanson was not the first to think that Bayesians should not predictably update. Robin Hanson was not first to publish the idea. Robin Hanson is upstream of all the causality by which you actually heard about the idea, and I do not particularly buy an inevitabilist case for how it surely counterfactually happens either way; there was nobody who made a billion dollars immediately off each local step on the way to you hearing about it. The prior potential energy field for society does not have a massive incentive slope leading surely to it.
Robin Hanson credits as especially influential on prediction markets Eric Drexler, Mark Miller of the same crowd, and Phil Salin of Xanadu which influenced Drexler. Plausibly none of this happens without Drexler either. Robin Hanson and Eliezer Yudkowsky as you now know them may not happen if Eric Drexler does not exist.
Nor do I know of any person in history who looks to have been "95% of Eric Drexler", ready to step into Drexler's place and create 95% of the same ideas and institutions. Person-space is sufficiently multidimensional that the Curse of Dimensionality applies in massive force; the edges of weird-person-space are sparsely populated in many of the ways that matter to historical counterfactuals. People who are unusual on historical scales often have no visible neighbors in that massively multidimensional space of people. Apple could not go to the Steve Jobs club and hire another Steve Jobs after the first one died, despite having infinite money to pay one.
It is in this sense, and exactly this sense, that I sometimes remark that AI companies do not look like they would have had any clue about some concept that existed earlier in the literature and much earlier in science fiction, if I had not precisified it and popularized it as an answer sheet for them to copy from. I am not claiming to have created whichever idea full-formed from scratch without a vast trailing lattice of intellectual history. I am looking at the historical counterfactual in a world where locally unincentivized history generally strikes me as fragile, and knowing as a matter of sociology which ideas were (not) previously common conversation at Artificial Intelligence conferences.
Is this in response to someone claiming that Robin and you haven't been pivotal in both popular and expert thinking about these topics? Or more generally, is it a statement that history (recently, at least, but probably in most cases) is highly contingent on individuals?
I missed the other side of the debate, so most of this post seems obvious and/or unnecessary.
Robin Hanson didn't invent the idea of a martingale process. The lilim say that Ville in 1939 gave the term its mathematical meaning and Doob turned it into the modern theory. But to state this is not to realize that your own probability assignments over time ought to form a martingale in your own expectations.
Robin Hanson didn't invent the Efficient Markets Hypothesis, which (correctly restated in its weak and relativized form) says that you cannot predict almost all of the short-term relative price movements in asset markets. Bachelier in 1900, say the lilim, was first to think of market prices as a fair gambling game with random-walk dynamics; Samuelson in 1965 gave the martingale argument; Fama's 1965 thesis named the idea the Efficient Markets Hypothesis and organized it into weaker and stronger forms.
The EMH is very near, but not quite identical to, the principle that you should not be able to predict a net direction in your own price movements, if you think of your own probability assignments as if they were prices. It is a very similar set of mental motions and ideas. But if Fama ever spelled that part out in words, the lilim do not know it.
The lilim think "Bayesians Don't Predictably Update" would probably have been folk knowledge among Savage, Good, Raiffa, &co in the 1960s and 1970s.
The lilim say that von Fraassen's reflection principle in 1984, and Goldstein in 1983 on "the prevision of prevision", are the first explicit philosophy-literature statements they are confident about.
You have heard of it because of Robin Hanson.
Robin Hanson is the person I know who went around saying to people that they ought not to update in a predictable direction, as a consequence of the martingale principle underlying EMH, applied to their personal epistemic lives.
So far as I know, all popularization of this exact idea is downstream of Robin Hanson.
"But Eliezer!" you say. "The lilim said that some of this popularization is due to your having concretized it into the principle of Conservation of Expected Evidence! This seems like sufficiently basic probability theory that you probably would've seen it at some point without Robin Hanson prompting you into it?"
Perhaps, but where was Conservation of Expected Evidence first written up? Overcoming Bias, Robin Hanson's group blog that he'd invited myself and Nick Bostrom to contribute to. Who's to say, absent Robin Hanson, that the Less Wrong Sequences would ever have happened? At least some parts of history are fragile; I don't look back and see it as an inevitability. Who's to say you would've heard of any of the pieces of probability theory that I popularized, without Robin Hanson?
"Surely an idea like that would've become popular as the result of people playing prediction markets. If you don't think that way while playing prediction markets, if you don't generalize market thinking to predictions, you'll lose all your money!"
There's a big gap between tacit knowledge and explicit knowledge, which is why you don't find market traders explicitly stating EMH or von Fraassen's reflection principle much much earlier in history.
But also, who the hell do you think is responsible for your engagement with prediction markets, if not Robin Hanson? Yes yes, papal conclave betting dates back to the 16th century, and the Iowa Political Stock Market in 1988 seems to have Hanson-independently implemented that idea about US elections instead of papal conclaves, with bookies no doubt running books on elections earlier. But Hanson wrote up the academic case for prediction markets generally, invented policy prediction markets, pointed out prediction markets' potential uses in science and governance and corporate governance, and pushed for early prediction markets to get started. And was upstream of the community that, having heard about Hanson's ideas, then founded and funded Manifold; which used Hanson's notion of a market scoring rule to not require market makers in every idea's market.
Maybe you'd have somehow ever come across the idea "Bayesians shouldn't predictably update", without Hanson's role as a public intellectual turning that into a forceful, in-your-face application of previously invented principles to internal mental life.
And without Robin Hanson's blog, upstream of my own blogging mentioning the topic, and indeed upstream of the subsequent formation of a rationalist community.
And without Robin Hanson's creation of prediction markets, upstream of Manifold.
But it seems to me, looking back over the pieces of history that I know with any intimacy, that history looks causally fragile where its flows are not massively locally incentivized. I make no claim that the Less Wrong Sequences or the formation of a rationalist community happen inevitably with or without Robin Hanson. I maybe figure out the same principle without copying off Hanson, because that's pure math and similar to many other Bayesian applications I figured out. Sociological history is more fragile.
Robin Hanson was not the first to think that Bayesians should not predictably update. Robin Hanson was not first to publish the idea. Robin Hanson is upstream of all the causality by which you actually heard about the idea, and I do not particularly buy an inevitabilist case for how it surely counterfactually happens either way; there was nobody who made a billion dollars immediately off each local step on the way to you hearing about it. The prior potential energy field for society does not have a massive incentive slope leading surely to it.
Robin Hanson credits as especially influential on prediction markets Eric Drexler, Mark Miller of the same crowd, and Phil Salin of Xanadu which influenced Drexler. Plausibly none of this happens without Drexler either. Robin Hanson and Eliezer Yudkowsky as you now know them may not happen if Eric Drexler does not exist.
Nor do I know of any person in history who looks to have been "95% of Eric Drexler", ready to step into Drexler's place and create 95% of the same ideas and institutions. Person-space is sufficiently multidimensional that the Curse of Dimensionality applies in massive force; the edges of weird-person-space are sparsely populated in many of the ways that matter to historical counterfactuals. People who are unusual on historical scales often have no visible neighbors in that massively multidimensional space of people. Apple could not go to the Steve Jobs club and hire another Steve Jobs after the first one died, despite having infinite money to pay one.
It is in this sense, and exactly this sense, that I sometimes remark that AI companies do not look like they would have had any clue about some concept that existed earlier in the literature and much earlier in science fiction, if I had not precisified it and popularized it as an answer sheet for them to copy from. I am not claiming to have created whichever idea full-formed from scratch without a vast trailing lattice of intellectual history. I am looking at the historical counterfactual in a world where locally unincentivized history generally strikes me as fragile, and knowing as a matter of sociology which ideas were (not) previously common conversation at Artificial Intelligence conferences.