All of basil.halperin's Comments + Replies

Very cool!

To deal with the imperfect compliance of the randomization, you could use the "instrumental variables" approach. In this case, since it is (one-sided) noncompliance in an experiment, this amounts to:

1. Using all of your data (ie, not subsetting the data to periods in which you complied with randomization)
2. Dividing the observed treatment effect by the fraction of time in which you complied (if I understand correctly, this is 0.5)

I emphasize that this is a very simple econometric technique and does not rely on unreasonable assumptions ("Wald estimator" is another search term here).

Isn't the fact that Manifold is not really a real-money prediction market very important here? If there was real money on the table, for example, it's less likely that the 1/1/26 market would have been "forgotten" -- the original traders would have had money on the line to discipline their attention.

Every time someone calls Manifold (or Metaculus) a "prediction market", god kills an arbitrageur [even though both platforms are still great!].

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

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)

(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 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!

Interesting thanks -- an ongoing RCT, ending in September this year, looks relevant.

(The titular insight seems pretty deep, thanks for sharing this)

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.