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.
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.
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.
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.