All of basil.halperin's Comments + Replies

Since the multiple upvotes seem indicate multiple people looking for an explanation: a link

This isn't REALLY the point of your (nice) piece, but the title provides an opportunity to plant a flag and point out: "predictably updating" is not necessarily bad or irrational. Unfortunately I don't have time to write up the full argument right now, hopefully eventually, but, TLDR:

  • Bayesian rational learning about a process can be very slow...
  • ...which leads to predictable updating...
  • ...especially when the long-run dynamics underlying the process are slow-moving.

In macroeconomics, this has recently been discussed in detail by Farmer, Nakamura, and Steinss... (read more)

Scott Sumner offers some comments here FWIW, copying and pasting:

I certainly believe the BOJ policy had the effect of boosting Japan’s real GDP, but the figure cited by Yudkowsky (“trillions of dollars”) seems excessive.

A few points:

1. In the long run, money is neutral. Hence monetary stimulus won’t impact the long run level of Japan’s RGDP or employment.

2. There’s a lot of evidence that Kuroda’s policies boosted Japan’s NGDP.

So here’s the issue. How much evidence is there that faster NGDP growth boosted Japan’s real economy (and employment) for a period o

... (read more)
4Matthew Barnett10mo
I'm happy that Scott Sumner commented. I think his analysis is reasonable, and I roughly agree with what he said. My only major complaint is that I think he might have misread the extent to which my article was intended as a criticism of his policy recommendations as opposed to Eliezer's specific commentary. I think it's plausible that the new monetary policy had a modest but positive counterfactual impact on RGDP over several years. I just don't think that's the impression Eliezer gave in the book when he provided the example.

1. Very interesting, thanks, I think this is the first or second most interesting comment we've gotten.

2. I see that you are suggesting this as a possibility, rather than a likelihood, but I'll note at least for other readers that -- I would bet against this occurring, given central banks' somewhat successful record at maintaining stable inflation and desire to avoid deflation. But it's possible!

3. Also, I don't know if inflation-linked bonds in the other countries we sample -- UK/Canada/Australia -- have the deflation floor. Maybe they avoid this issue.

4.... (read more)

It appears the UK's index-linked gilts, at least, don't have this structural issue. See "redemption payments" on page 6 of this document, or put in a sufficiently large negative inflation assumption here.

(A confusing way of writing "probability")

"log odds" : "probability"


"epistemic status" : "confidence level"


(there are useful reasons to talk about log odds instead of probabilities, as in the post @Morpheus links to, but it also does seem like there's some gratuitous use of jargon going on)

Thanks, this gives me another chance to try to lay out this argument (which is extra-useful because I don't think I've hit upon the clearest way of making the point yet):

People are made of atoms. People make choices. Nothing is inconsistent about that.

Absolutely. But "choice", like agency, is a property of the map not of the territory. If you full specify the initial position of all of the atoms making up my body and their velocities, etc. -- then clearly it's not useful to speak of me making any choices. You are in the position of Laplace's demon: you kno... (read more)

Here's a related old comment from @Anders_H that I think frames the issue nicely, for my own reference at the very least:

Any decision theory depends on the concept of choice: If there is no choice, there is no need for a decision theory. I have seen a quote attributed to Pearl to the effect that we can only talk about "interventions" at a level of abstraction where free will is apparent. This seems true of any decision theory. 


(He goes on to say -- less relevantly for the discussion here, but again I like the framing so am recording to remind fu... (read more)

Re: the perfect deterministic twin prisoner's dilemma:

You’re a deterministic AI system, who only wants money for yourself (you don’t care about copies of yourself). The authorities make a perfect copy of you, separate you and your copy by a large distance, and then expose you both, in simulation, to exactly identical inputs (let’s say, a room, a whiteboard, some markers, etc). You both face the following choice: either (a) send a million dollars to the other (“cooperate”), or (b) take a thousand dollars for yourself (“defect”). 

If we say there are two... (read more)

This doesn't make any sense to me. People are made of atoms. People make choices. Nothing is inconsistent about that. If two people were atomically identical, they'd make the same choices. But that wouldn't change anything about how the choice was happening. Right? Suppose we made an atom-by-atom copy of you, as in the post. Does the existence of this copy mean that you stop choosing your own decisions? Have I just misunderstood what you're saying?
Here's a related old comment from @Anders_H that I think frames the issue nicely, for my own reference at the very least:   (He goes on to say -- less relevantly for the discussion here, but again I like the framing so am recording to remind future-me -- "CDT and TDT differ in how they operationalize choice, and therefore whether the decision theories are consistent with free will. In Causal Decision theory, the agents choose actions from a choice set. In contrast, from my limited understanding of TDT/UDT, it seems as if agents choose their source code. This is not only inconsistent with my (perhaps naive) subjective experience of free will, it also seems like it will lead to an incoherent concept of "choice" due to recursion.")

This is excellent, thank you! I don't know of a solution to this problem, but FWIW it seems that webclippers somewhat break on these -- e.g. (1) Instapaper doesn't show the footnote number in the body of the text, only the footnote text at the end of the post; (2) Pocket shows the footnote number in the body of the text, but no where shows the footnote text itself.

Thanks again!

It's a complement, not a substitute: 

  1. I find Anki/spaced repetition extremely useful for mastering the vocabulary of a foreign language (or, in non-language settings, getting the basics down pat)
  2. But speaking fluently requires -- un(?)-surprisingly -- actually speaking

But mastering those basics is extremely useful!

As Michael Nielsen puts it: imagine trying to write a French sonnet if you have to look up the translation for every word you think of using. Mastering the rote basics is essential, in many settings, for mastery of the larger project -- and that's what spaced repetition does well.

This is not exactly central to your main argument, but I think it's worth pointing out, since this is something I see even economists I really respect like Scott Sumner being imprecise about: Even if markets are efficient (and I agree they pretty much are!), then prices can still be predictable.

This is the standard view in academic asset pricing theory. The trick is that: under the EMH, risk-adjusted returns must follow a random walk, not that returns themselves must follow a random walk. I have an essay explaining this in more detail for the curious.

2Panashe Fundira4y
Thank you for writing such a clear article on the issue. Cleared up my confusion around EMH, and especially how it differs from the random walk hypothesis. I'll definitely reference this article when people bring up EMH.