Harry Potter and the Methods of Rationality discussion thread, part 3

Unnamed

Update: This post has also been superseded - new comments belong in the latest thread.

The second thread has now also exceeded 500 comments, so after 42 chapters of MoR it's time for a new thread.

Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.

A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.

Update: This post has also been superseded - new comments belong in the latest thread.

The second thread has now also exceeded 500 comments, so after 42 chapters of MoR it's time for a new thread.

From the first thread:

Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.

A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.

I have a question about TDT's application in 33 of HP:MoR.

I didn't say you should just automatically cooperate. Not on a true Prisoner's Dilemma like this one. What I said was that when you choose, you shouldn't think like you're choosing for just yourself, or like you're choosing for everyone. You should think like you're choosing for all the people who are similar enough to you that they'll probably do the same thing you do for the same reasons.

Should businessmen collude on one-shot pricing? The decision theory I learned in school says "Never!," but I can see Harry's beliefs going in either direction.

Links to a good summary of TDT are welcome.

Should businessmen collude on one-shot pricing?

All they need to do is find someone who can help enforce the decision, or make it matter reputationally to friends, or iterate it, and they don't need to worry about whether they're doing the same thing for the same reasons.

0PhilGoetz16y

I don't understand TDT, and the people who write about it are very smart; but that passage made it sound like sympathetic magic. You're not choosing for all the people who are similar to you. You can argue that doing so leads to better outcomes in PDs - but then you're really just arguing for cooperation, not choosing the decision theory that maximizes your utility. "All the people who are similar enough to you that they'll probably do the same thing you do for the same reasons" just means "All the other cooperators". So saying "I implement timeless decision theory" seems to be a way to clothe saying "I cooperate on PD" in bogus Bayesian respectability.

12Perplexed16y

Well, not really good. Merely best.

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Harry Potter and the Methods of Rationality discussion thread, part 3

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Harry Potter and the Methods of Rationality discussion thread, part 3

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