In parallel, if I am to compare two independent scenarios, the at-least-one-in-ten-billion odds that I'm hallucinating all this, and the darned-near-zero odds of a Pascal's Mugging attempt, then I should be spending proportionately that much more time dealing with the Matrix scenario than that the Pascal's Mugging attempt is true

That still sounds wrong. You appear to be deciding on what to precompute for purely by probability, without considering that some possible futures will give you the chance to shift more utility around.

If I don't know anything about Newcomb's problem and estimate a 10% chance of Omega showing up and posing it to me tomorrow, I'll definitely spend more than 10% of my planning time for tomorrow reading up on and thinking about it. Why? Because I'll be able to make far more money in that possible future than the others, which means that the expected utility differentials are larger, and so it makes sense to spend more resources on preparing for it.

The I-am-undetectably-insane case is the opposite of this, a scenario that it's pretty much impossible to usefully prepare for.

And a PM scenario is (at least for an expected-utility maximizer) a more extreme variant of my first scenario - low probabilities of ridiculously large outcomes, that are because of that still worth thinking about.

Continuity and independence.

Continuity: Consider the scenario where each of the [LMN] bets refer to one (guaranteed) outcome, which we'll also call L, M and N for simplicity.

Let U(L) = 0, U(M) = 1, U(N) = 10**100

For a simple EU maximizer, you can then satisfy continuity by picking p=(1-1/10**100). A PESTI agent, OTOH, may just discard a (1-p) of 1/10**100, which leaves no other options to satisfy it.

The 10**100 value is chosen without loss of generality. For PESTI agents that still track probabilities of this magnitude, increase it until they don't.

Independence: Set p to a number small enough that it's Small Enough To Ignore. At that point, the terms for getting L and M by that probability become zero, and you get equality between both sides.

Thus, I can never be more than one minus one-in-ten-billion sure that my sensory experience is even roughly correlated with reality. Thus, it would require extraordinary circumstances for me to have any reason to worry about any probability of less than one-in-ten-billion magnitude.

No. The reason not to spend much time thinking about the I-am-undetectably-insane scenario is not, in general, that it's extraordinarily unlikely. The reason is that you can't make good predictions about what would be good choices for you in worlds where you're insane and totally unable to tell.

This holds even if the probability for the scenario goes up.

It's the most important problem of this time period, and likely human civilization as a whole. I donate a fraction of my income to MIRI.

Which means that if we buy this [great filter derivation] argument, we should put a lot more weight on the category of 'everything else', and especially the bits of it that come before AI. To the extent that known risks like biotechnology and ecological destruction don't seem plausible, we should more fear unknown unknowns that we aren't even preparing for.

True in principle. I do think that the known risks don't cut it; some of them might be fairly deadly, but even in aggregate they don't look nearly deadly enough to contribute much to the great filter. Given the uncertainties in the great filter analysis, that conclusion for me mostly feeds back in that direction, increasing the probability that the GF is in fact behind us.

Your SIA doomsday argument - as pointed out by michael vassar in the comments - has interesting interactions with the simulation hypothesis; specifically, since we don't know if we're in a simulation, the bayesian update in step 3 can't be performed as confidently as you stated. Given this, "we really can't see a plausible great filter coming up early enough to prevent us from hitting superintelligence" is also evidence for this environment being a simulation.

This issue is complicated by the fact that we don't really know how much computation our physics will give us access to, or how relevant negentropy is going to be in the long run. In particular, our physics may allow access to (countably or more) infinite computational and storage resources given some superintelligent physics research.

For Expected Utility calculations, this possibility raises the usual issues of evaluating potential infinite utilities. Regardless of how exactly one decides to deal with those issues, the existence of this possibility does shift things in favor of prioritizing for safety over speed.

I used "invariant" here to mean "moral claim that will hold for all successor moralities".

A vastly simplified example: at t=0, morality is completely undefined. At t=1, people decide that death is bad, and lock this in indefinitely. At t=2, people decide that pleasure is good, and lock that in indefinitely. Etc.

An agent operating in a society that develops morality like that, looking back, would want to have all the accidents that lead to current morality to be maintained, but looking forward may not particularly care about how the remaining free choices come out. CEV in that kind of environment can work just fine, and someone implementing it in that situation would want to target it specifically at people from their own time period.

That does not sound like much of a win. Present-day humans are really not that impressive, compared to the kind of transhumanity we could develop into. I don't think trying to reproduce entites close to our current mentality is worth doing, in the long run.

While that was phrased in a provocative manner, there /is/ an important point here: If one has irreconcilable value differences with other humans, the obvious reaction is to fight about them; in this case, by competing to see who can build an SI implementing theirs first.

I very much hope it won't come to that, in particular because that kind of technology race would significantly decrease the chance that the winning design is any kind of FAI.

In principle, some kinds of agents could still coordinate to avoid the costs of that kind of outcome. In practice, our species does not seem to be capable of coordination at that level, and it seems unlikely that this will change pre-SI.