The "simulation" in this case could entirely be in the Predictor's head. But I concede the point, and shift to a weaker position:
In the original Newcomb problem, the nature of the boxes is decided by a perfect or near-perfect prediction of your decision; it's predicting your decision, and is for all intents and purposes taking your decision into account. (Yes, it -could- be using genetics, but there's no reason to elevate that hypothesis.)
In the medical Newcomb problem, the nature of the boxes is decided by your genetics, which have a very strong correlation with your decision; it is still predicting your decision, but by a known algorithm which doesn't take your decision into account.
Your decision in the first case should account for the possibility that it accurately predicts your decision - unless you place .1% or greater odds on it mis-calculating your decision, you should one-box. [Edited: Fixed math error that reversed calculation versus mis-calculation.]
Your decision in the second case should not - your genetics are already what your genetics are, and if your genetics predict two-boxing, you should two-box because $1,000 is better than nothing, and if your genetics predict one-boxing, you should two-box because $1,001,000 is better than $1,000,000.
In the original Newcomb problem, the nature of the boxes is decided by a perfect or near-perfect prediction of your decision; it's predicting your decision, and is for all intents and purposes taking your decision into account.
Actually, I am not sure about even that weaker position. The Nozick article stated:
...If a state is part of the explanation of deciding to do an action (if the decision is made) and this state is already fixed and determined, then the decision, which has not yet been made, cannot be part of the explanation of the state's obtaining.
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.