Thanks! Ah, I'm probably just typical-minding like there's no tomorrow, but I find it inconceivable to place much value on the amount of branches you exist in. The perceived continuation of your consciousness will still go on as long as there are beings with your memories in some branch: in general, it seems to me that if you say you "want to keep living", you mean you want there to be copies of you in some or the possible futures, waking up the next morning doing stuff present-you would have done, recalling what present-you thought yesterday, and so on (in addition you will probably want a low probability for this future to include significant suffering). Likewise, if you say you "want to see humanity flourish indefinitely", you want a future that includes your biological or cultural peers and offspring colonizing space and all that, remembering and cherishing many of the values you once had (sans significant suffering). To me it seems impossible to assign value to the amount of MWI-copies of you, not least because there is no way you could even conceive their number, or usually make meaningful ethical decisions where you weigh their amounts.* Instead, what matters overwhelmingly more is the probability of any given copy living a high quality life.
just the proportion of branches where everything is stellar out of the total proportion of branches where you are alive
Yes, this is obvious of course. What I meant was exactly this, because from the point of view of a set of observers, eliminating the set of observers from a branch <=> rendering the branch irrelevant, pretty much.
which isn't so important.
To me it did feel like this is obviously what's important, and the branches where you don't exist simply don't matter - there's no one there to observe anything after all, or judge the lack of you to be a loss or morally bad (again, not applicable to individual humans).
If I learned today that I have a 1% chance to develop a maybe-terminal, certainly suffering-causing cancer tomorrow, and I could press a button to just eliminate the branches where that happens, I would not have thought I am committing a moral atrocy. I would not feel like I am killing myself just because part of my future copies never get to exist, nor would I feel bad for the copies of the rest of all people - no one would ever notice anything, vast amounts of future copies of current people would wake up just like they thought they would the next morning, and carry on with their lives and aspirations. But this is certainly something I should learn to understand better before anyone gives me a world-destroying cancer cure button.
*Which is one main difference when comparing this to regular old population ethics, I suppose.
To me it seems impossible to assign value to the amount of MWI-copies of you, not least because there is no way you could even conceive their number, or usually make meaningful ethical decisions where you weigh their amounts.
As it happens, you totally can (it's called the Born measure, and it's the same number as what people used to think was the probabilities of different branches occurring), and agents that satisfy sane decision-theoretic criteria weight branches by their Born measure - see this paper for the details.
...I would not feel like I am kill
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