I'm afraid I don't understand your point — could you please rephrase?

Linkpost: "Against dynamic consistency: Why not time-slice rationality?"

This got too long for a "quick take," but also isn't polished enough for a top-level post. So onto my blog it goes.

I’ve been skeptical for a while of updateless decision theory, diachronic Dutch books, and dynamic consistency as a rational requirement. I think Hedden's (2015) notion of time-slice rationality nicely grounds the cluster of intuitions behind this skepticism.

"I'll {take/lay} $100 at those odds, what's our resolution mechanism?" is an excellent clarification mechanism

I think one reason this has fallen out of favor is that it seems to me to be a type error. Taking $100 at some odds is a (hypothetical) decision, not a belief. And the reason you'd be willing to take $100 at some odds is, your credence in the statement is such that taking the bet would be net-positive.

I still feel like I don't know what having a strict preference or permissibility means — is there some way to translate these things to actions?

As an aspiring rational agent, I'm faced with lots of options. What do I do? Ideally I'd like to just be able to say which option is "best" and do that. If I have a complete ordering over the expected utilities of the options, then clearly the best option is the expected utility-maximizing one. If I don't have such a complete ordering, things are messier. I start by ruling out dominated options (as Maximality does). The options in the remaining set are all "permissible" in the sense that I haven't yet found a reason to rule them out.

I do of course need to choose an action eventually. But I have some decision-theoretic uncertainty. So, given the time to do so, I want to deliberate about which ways of narrowing down this set of options further seem most reasonable (i.e., satisfy principles of rational choice I find compelling).

(Basically I think EU maximization is a special case of “narrow down the permissible set as much as you can via principles of rational choice,^[1] then just pick something from whatever remains.” It’s so straightforward in this case that we don’t even recognize we’re identifying a (singleton) “permissible set.”)

Now, maybe you'd just want to model this situation like: "For embedded agents, 'deliberation' is just an option like any other. Your revealed strict preference is to deliberate about rational choice." I might be fine with this model.^[2] But:

• For the purposes of discussing how {the VOI of deliberation about rational choice} compares to {the value of going with our current “best guess” in some sense}, I find it conceptually helpful to think of “choosing to deliberate about rational choice” as qualitatively different from other choices.
• The procedure I use to decide to deliberate about rational choice principles is not “I maximize EV w.r.t. some beliefs,” it’s “I see that my permissible set is not a singleton, I want more action-guidance, so I look for more action-guidance.”

1. ^{^}

   "Achieve Pareto-efficiency" (as per the CCT) is one example of such a principle.

2. ^{^}

   Though I think once you open the door to this embedded agency stuff, reasoning about rational choice in general becomes confusing even for people who like precise EV max.

It seems to me like you were like: "why not regiment one's thinking xyz-ly?" (in your original question), to which I was like "if one regiments one thinking xyz-ly, then it's an utter disaster" (in that bullet point), and now you're like "even if it's an utter disaster, I don't care

My claim is that your notion of "utter disaster" presumes that a consequentialist under deep uncertainty has some sense of what to do, such that they don't consider ~everything permissible. This begs the question against severe imprecision. I don't really see why we should expect our pretheoretic intuitions about the verdicts of a value system as weird as impartial longtermist consequentialism, under uncertainty as severe as ours, to be a guide to our epistemics.

I agree that intuitively it's a very strange and disturbing verdict that ~everything is permissible! But that seems to be the fault of impartial longtermist consequentialism, not imprecise beliefs.

The branch that's about sequential decision-making, you mean? I'm unconvinced by this too, see e.g. here — I'd appreciate more explicit arguments for this being "nonsense."

my response: "The arrow does not point toward most Sun prayer decision rules. In fact, it only points toward the ones that are secretly bayesian expected utility maximization. Anyway, I feel like this does very little to address my original point that there is this big red arrow pointing toward bayesian expected utility maximization and no big red arrow pointing toward Sun prayer decision rules."

I don't really understand your point, sorry. "Big red arrows towards X" only are a problem for doing Y if (1) they tell me that doing Y is inconsistent with doing [the form of X that's necessary to avoid leaving value on the table]. And these arrows aren't action-guiding for me unless (2) they tell me which particular variant of X to do. I've argued that there is no sense in which either (1) or (2) is true. Further, I think there are various big green arrows towards Y, as sketched in the SEP article and Mogensen paper I linked in the OP, though I understand if these aren't fully satisfying positive arguments. (I tentatively plan to write such positive arguments up elsewhere.)

I'm just not swayed by vibes-level "arrows" if there isn't an argument that my approach is leaving value on the table by my lights, or that you have a particular approach that doesn't do so.

Addendum: The approach I take in "Ex ante sure losses are irrelevant if you never actually occupy the ex ante perspective" has precedent in Hedden (2015)'s defense of "time-slice rationality," which I highly recommend. Relevant quote:

I am unmoved by the Diachronic Dutch Book Argument, whether for Conditionalization or for Reflection. This is because from the perspective of Time-Slice Rationality, it is question-begging. It is uncontroversial that collections of distinct agents can act in a way that predictably produces a mutually disadvantageous outcome without there being any irrationality. The defender of the Diachronic Dutch Book Argument must assume that this cannot happen with collections of time-slices of the same agent; if a collection of time-slices of the same agent predictably produces a disadvantageous outcome, there is ipso facto something irrational going on. Needless to say, this assumption will not be granted by the defender of Time-Slice Rationality, who thinks that the relationship between time-slices of the same agent is not importantly different, for purposes of rational evaluation, from the relationship between time-slices of distinct agents.

I reject the premise that my beliefs are equivalent to my betting odds. My betting odds are a decision, which I derive from my beliefs.

It's not that I "find it unlikely on priors" — I'm literally asking what your prior on the proposition I mentioned is, and why you endorse that prior. If you answered that, I could answer why I'm skeptical that that prior really is the unique representation of your state of knowledge. (It might well be the unique representation of the most-salient-to-you intuitions about the proposition, but that's not your state of knowledge.) I don't know what further positive argument you're looking for.