I am currently learning about the basics of decision theory, most of which is common knowledge on LW. I have a question, related to why EDT is said not to work.
Consider the following Newcomblike problem: A study shows that most people who two-box in Newcomblike problems as the following have a certain gene (and one-boxers don't have the gene). Now, Omega could put you into something like Newcomb's original problem, but instead of having run a simulation of you, Omega has only looked at your DNA: If you don't have the "two-boxing gene", Omega puts $1M into box B, otherwise box B is empty. And there is $1K in box A, as usual. Would you one-box (take only box B) or two-box (take box A and B)? Here's a causal diagram for the problem:
Since Omega does not do much other than translating your genes into money under a box, it does not seem to hurt to leave it out:
I presume that most LWers would one-box. (And as I understand it, not only CDT but also TDT would two-box, am I wrong?)
Now, how does this problem differ from the smoking lesion or Yudkowsky's (2010, p.67) chewing gum problem? Chewing Gum (or smoking) seems to be like taking box A to get at least/additional $1K, the two-boxing gene is like the CGTA gene, the illness itself (the abscess or lung cancer) is like not having $1M in box B. Here's another causal diagram, this time for the chewing gum problem:
As far as I can tell, the difference between the two problems is some additional, unstated intuition in the classic medical Newcomb problems. Maybe, the additional assumption is that the actual evidence lies in the "tickle", or that knowing and thinking about the study results causes some complications. In EDT terms: The intuition is that neither smoking nor chewing gum gives the agent additional information.
I am not entirely sure, I understand your TDT analysis, maybe that's because I don't understand TDT that well. I assumed that TDT would basically just do what CDT does, because there are no simulations of the agent involved. Or do you propose that checking for the gene is something like simulating the agent?
It does not seem to be more evil than Newcomb's problem, but I am not sure, what you mean by "evil". For every decision theory, it is possible, of course, to set up some decision problem, where this decision theory loses. Would you say that I set up the "genetic Newcomb problem" specifically to punish CDT/TDT?
The role that would normally be played by simulation is here played by a big evidential study of what people with different genes do. This is why it matters whether the people in the study are good decision-makers or not - only when the people in the study are in a position similar to my own do they fulfill this simulation-like role.
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