You seem to posit reasons why strategies might exist, but really this is a concrete problem. “Name some strategies”.
So I think our disagreement might be this:
I think that exploring why strategies might exist is an interesting and important question on its own, separate from articulating a concrete, step-by-step procedure for doing so.
You seem to accept (?) that tractable strategies in general might plausibly exist, but think that this is uninteresting on its own. The more interesting question for you is in naming and proving a specific one.
The reason that I think articulating why strategies might exist is that I’m a dogmatic EMH fundamentalist. When a person gives investment advice, I have historically ignored it, the same why I ignore it when somebody makes an argument for why I should consider using heroin, or committing suicide. Those behaviors are on my “no” list. I don’t intellectually engage with arguments in favor of them, and short-circuit the updating of my priors.
Likewise, the EMH has put investment advice (aside from “invest in index funds”) on my “no” list. I follow an iron law of not engaging with investment advice.
In concrete terms, this “iron law” plays out a bit like this:
Bob claims to have some investment advice.
I say “Lots of people have investment advice. Why should I listen to yours?”
Bob says, “Just think about the reasoning! It makes total sense!”
I say “I am epistemically helpless in this matter and need to see empirical proof that it works.”
Bob says, “I’ve used it already to make a bunch of money!”
I say “How do I know you weren’t just lucky?”
Bob says, “I can show you statistical data that proves that’s extremely unlikely to be true.”
I say “How do I know the market hasn’t absorbed this information, so that your strategy will fail in the future?”
Bob says, “I’ve kept it a secret until now, and I’m sharing it with you out of the goodness of my heart.”
I say “How do I know you’re not lying or confused?” And that’s the end of the conversation.
The epistemic helplessness/fundamental trust problem here then precludes me from even starting to listen to Bob in the first place.
Hence, in order to ever get around to conceiving of, or even considering, a specific investment strategy, it’s first necessary to argue against this pattern of thinking. That’s what I’m trying to do here.
Hopefully, this illuminates why I don’t consider it useful to try and articulate specific investment strategies, without addressing this more fundamental question first. My prior on any public investment strategy beating the market is so low that it has precluded me from even going there.
To change that, I need to understand why my priors should be high enough to consider specific investment strategies in the first place.
The reason that I think articulating why strategies might exist is that I’m a dogmatic EMH fundamentalist. When a person gives investment advice, I have historically ignored it, the same why I ignore it when somebody makes an argument for why I should consider using heroin, or committing suicide. Those behaviors are on my “no” list. I don’t intellectually engage with arguments in favor of them, and short-circuit the updating of my priors
Likewise, the EMH has put investment advice (aside from “invest in index funds”) on my “no” list. I follow an iron law of not engaging with investment advice.
I would highly recommend reading the full introduction to Section 20 of Cochrane’s “Asset Pricing”. (The whole course is excellent) Roughly he takes you through the progress academic finance has made since the 1970s, whilst not repudiating EMH, finding reasons why “invest in index funds” isn’t necessarily the whole story for investors.
So I think our disagreement might be this:
I think that exploring why strategies might exist is an interesting and important question on its own, separate from articulating a concrete, step-by-step procedure for doing so.
You seem to accept (?) that tractable strategies in general might plausibly exist, but think that this is uninteresting on its own. The more interesting question for you is in naming and proving a specific one.
The reason that I think articulating why strategies might exist is that I’m a dogmatic EMH fundamentalist. When a person gives investment advice, I have historically ignored it, the same why I ignore it when somebody makes an argument for why I should consider using heroin, or committing suicide. Those behaviors are on my “no” list. I don’t intellectually engage with arguments in favor of them, and short-circuit the updating of my priors.
Likewise, the EMH has put investment advice (aside from “invest in index funds”) on my “no” list. I follow an iron law of not engaging with investment advice.
In concrete terms, this “iron law” plays out a bit like this:
Bob claims to have some investment advice.
I say “Lots of people have investment advice. Why should I listen to yours?”
Bob says, “Just think about the reasoning! It makes total sense!”
I say “I am epistemically helpless in this matter and need to see empirical proof that it works.”
Bob says, “I’ve used it already to make a bunch of money!”
I say “How do I know you weren’t just lucky?”
Bob says, “I can show you statistical data that proves that’s extremely unlikely to be true.”
I say “How do I know the market hasn’t absorbed this information, so that your strategy will fail in the future?”
Bob says, “I’ve kept it a secret until now, and I’m sharing it with you out of the goodness of my heart.”
I say “How do I know you’re not lying or confused?” And that’s the end of the conversation.
The epistemic helplessness/fundamental trust problem here then precludes me from even starting to listen to Bob in the first place.
Hence, in order to ever get around to conceiving of, or even considering, a specific investment strategy, it’s first necessary to argue against this pattern of thinking. That’s what I’m trying to do here.
Hopefully, this illuminates why I don’t consider it useful to try and articulate specific investment strategies, without addressing this more fundamental question first. My prior on any public investment strategy beating the market is so low that it has precluded me from even going there.
To change that, I need to understand why my priors should be high enough to consider specific investment strategies in the first place.
I would highly recommend reading the full introduction to Section 20 of Cochrane’s “Asset Pricing”. (The whole course is excellent) Roughly he takes you through the progress academic finance has made since the 1970s, whilst not repudiating EMH, finding reasons why “invest in index funds” isn’t necessarily the whole story for investors.
Thanks, this sounds very interesting. I appreciate all your thoughts in this comment thread and the recommendation as well.