It's ironic that Wei originally invented UDT in an attempt to figure out anthropic reasoning, but now we can see that it mostly pushes the problem under the rug.
I did point out
In general, Updateless Decision Theory converts anthropic reasoning problems into ethical problems.
in Torture vs. Dust vs. the Presumptuous Philosopher: Anthropic Reasoning in UDT. So I'm not trying it hide it or anything. :)
Thanks for that link, I'd read it but then forgot about it for some reason. it definitely belongs here :-)
The problem is, I just can't accept the idea that anthropic/ethical problems are "indeterminate" and that we should rely on our "intuitions". It seems that some anthropic problems must have well-defined solutions. If you take part in many successive experiments with observer-splitting, you will observe some limiting frequencies, but we have no clue what these frequencies will be. Do they depend on the thickness of the silicon wafers used to build our computers? Or do they depend on the algorithms running within our brains?
As argued here, debates about probability can be profitably replaced with decision problems. This often dissolves the debate - there is far more agreement as to what decision sleeping beauty should take than on what probabilities she should use.
The concept of subjective anticipation or subjective probabilities that cause such difficulty here, can, I argue, be similarly replaced by a simple decision problem.
If you are going to be copied, uncopied, merged, killed, propagated through quantum branches, have your brain tasered with amnesia pills while your parents are busy flipping coins before deciding to reproduce, and are hence unsure as to whether you should subjectively anticipated being you at a certain point, the relevant question should not be whether you feel vaguely connected to the putative future you in some ethereal sense.
Instead the question should be akin to: how many chocolate bars would your putative future self have to be offered, for you to forgo one now? What is the tradeoff between your utilities?
Now, altruism is of course a problem for this approach: you might just be very generous with copy #17 down the hallway, he's a thoroughly decent chap and all that, rather than anticipating being him. But humans can generally distinguish between selfish and altruistic decisions, and the setup can be tweaked to encourage the maximum urges towards winning, rather than letting others win. For me, a competitive game with chocolate as the reward would do the trick...
Unlike for the sleeping beauty problem, this rephrasing does not instantly solve the problems, but it does locate them: subjective anticipation is encoded in the utility function. Indeed, I'd argue that subjective anticipation is the same problem as indexical utility, with a temporal twist thrown in.