I don't get #2 - you need a better description of "measures as" in order to dissolve this question.
I suspect (but am not sure - it'll depend on your measurements) you'll also need to be very careful to distinguish "identical" from "very similar". If two consciousnesses are in different Everett branches, there is something distinct about them and they're not identical.
By "measures as" I mean as in what was the probability to experience exact this moment, from the set of all possible moments that "exists" (or can be experienced). And by "measures as 1" I mean, that if several physical "carriers" produces exact same experience, that counts as 1 experience in the grand total set of experiences, and probability to feel exactly that is 1/(count of all different experiences). Now I know this is controversial and counter intuitive. But still this is quite plausible, given what we even know about consciousness. Like, if consciousness emerges on the level of algorithms and logic, then why would it care, how many physical things produces it? If one were asked, how many movies about human pretending to be blue alien on planet Pandora does he know, the answer would probably be 1 and not the number of digital Avatar copies ever made.
Hmm. I still think you need rigor in how you know what differences are important and which are ignored. There is no such thing as actually identical universe-states across branches, so you're somehow collapsing different physical things into "same" experience.
If you asked how many movies does a person know on that, they'd likely say 1, because they're collapsing all the copies, which vary only trivially. If you ask "what's the probability that a randomly chosen disc in a used DVD store is Avatar", then the ratio of individual copies matters.
The purpose and type of comparison matters a lot in determining whether distinct things are fungible.
To be clear, I totally get that two experiences can be indistinguishable as anticipation or memory for an entity. I'm just not sure why it matters when counting universe-states for the purposes of a probability estimate.
The truth is that we don't know.
First, both assumptions may be false.
For example, "many worlds" is over simplification of the Everett's theory. In the last one only Schrodinger function exists, and it is complex, not real, which prevent us from numerical calculating of the number of the worlds and observers. Quantum anthropic becomes difficult. I am now reading an article on the topic, and hope to understand it better. http://arxiv.org/pdf/1405.7577v3.pdf "Self-Locating Uncertainty and the Origin of Probability in Everettian Quantum Mechanics".
Number 2 will result in catastrophic consequences for my future. Because I have only one normal next moment - there I will continue to write this comment, and thousands on unpleasant next moments, there something disruptive will happen with me, most of them will be different catastrophic events - a plane would hit my house, and so on.
I think that different way of calculating measure should be used, where measure is proportional to the energy of calculations. This idea imply existence of minimal "plank observer", and all other observers are interoperated as number parallely running plank observers. This number could help to distinguish between measure of existence of different copies of me, if they are running on different computers.
It does not solve your problem unfortunately, because here we have two completely different types of carriers.
I agree with criticism for 2 assumption. Although I have this intuition (based on possibly very wrong intuitions I have about QM), that argument still works even without it: Imagine same human runs the simulation. Then he goes to another table where he runs spin measuring experiment, with 50/50 probability of getting either up or down. After seeing the result, there is now two different consciousness of him, but there is still just one copy of simulated brains as they did not saw the result.
2: All identical consciousnesses measures as 1 in anthropics . So if we have set of consciousness: 1xA,1xB and 1000000xC, it is still 1/3 chance, to perceive being C.
Why do you take this assumption? It depends on the relative measure of the consciousnesses. Each one is equally likely and occur at equal measure across the multiverse (or at least, quantum physics strongly hints that they do), if one timeline leads to A, another leads to B, and 1000000 others lead to C, the odds of finding yourself with C are 1000000:2. This does not seem controversial.
Imagine a cosnciousness as a binary string. If I told you that you were being assigned 1000002 binary strings, and that all but two of them were the pattern C, why would you not expect C?
The problem here is that we are talking about two different concepts - experienced moments (as in antophics) and Everett branches (as in Many Words). There is a way to think of them as the same, but they not necessary are. Like if there is Bob before measuring spin, and two Bobs - Bob-up and Bob-down, after measuring, what is bigger probability to experience - being bob before measuring spin or being bob after measuring spin? (TBH I have no idea)
Lets assume few things:
1. Many Worlds is real.
2. All identical consciousnesses measures as 1 in anthropics . So if we have set of consciousness: 1xA,1xB and 1000000xC, it is still 1/3 chance, to perceive being C.
Now say some intelligent being (i.e. human) starts another human brain simulation on silicon chip. The operations it does are all discrete, so despite the chip splitting in to many chips in many worlds, the simulated consciousness itself remain just 1 (because of #2 assumption).
But that is not true for human who started the simulation as he differs somehow in every Everett branch and reaches billions different consciousnesses really fast.
Is there some mistake in reasoning, that real persons should heavily outweigh simulations, despite, how many of them are running, given such assumptions?