2009/3/11 Wei Dai <wei...@weidai.com>:
> Jack Mallah wrote:
>> They might not, but I'm sure most would; maybe not exactly that U, but a
>> lot closer to it.
> Can you explain why you believe that?
>> No. In U = Sum_i M_i Q_i, you sum over all the i's, not just the ones
>> that are similar to you. Of course your Q_i (which is _your_ utility per
>> unit measure for the observer i) might be highly peaked around those that
>> are similar to you, but there's no need for a precise cutoff in
>> similarity. And it's even very likely that it will have even higher peaks
>> around people that are not very much like you at all (these are the people
>> that you would sacrifice yourself for).
>> By contrast, in your proposal for U, you do need a precise cutoff, for
>> which there is no justification.
> Ok, I see what you're saying, and it is a good point. But most people
> already have a personal identity that is sufficiently well-defined in the
> current environment where mind copying is not possible, so in practice
> deciding which i's to sum over isn't a serious problem (yet).
The same problem would apply to calculating probabilities. If one copy
of me will see heads and a million copies of me who have a one
millionth degree of similarity to me will see tails, what is my
expectation of heads? I suggest introducing a factor R, a number
between 0 and 1 representing the degree of similarity to the original:
Pr(H) = M1R1 / (M1R1 + M2R2) = (1*1) / (1*1 + 10^6*10^-6) = 1/2
The analogous equation for utility, where Q is the absolute utility
experienced by an individual copy, is then:
U = (M1R1Q1 + M2R2Q2) / (M1R1 + M2R2)
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