Title: Theory / Unimportant / Human / Economics / Decision theory / functional - Yudkowsky
Tags: fromImplication

Name: Functional decision theory
Definition: «Which output of this decision procedure causes the best outcome?»
Page: 2, 7
Section: 1, 3
Abbreviation: FDT
Intuition: It is to subjunctive dependence as causal decision theory is to causal dependence.

Name: Causal decision theory
Definition: “Which physical act of mine causes the best outcome?”
Page: 2
Section: 1
Abbreviation: CDT

Name: Evidential decision theory
Definition: “Which physical act of mine would be the best news to hear I took?”
Page: 2
Section: 1
Abbreviation: EDT

Name: Psychological Twin Prisoner’s Dilemma
Definition: An agent and her twin must both choose to either “cooperate” or “defect.” If both cooperate, they each receive $1,000,000. 1 If both defect, they each receive $1,000. If one cooperates and the other defects, the defector gets $1,001,000 and the cooperator gets nothing. The agent and the twin know that they reason the same way, using the same considerations to come to their conclusions. However, their decisions are causally independent, made in separate rooms without communication. Should the agent cooperate with her twin?
Page: 2
Section: 1
Kind: Dilemma

Question: Psychological Twin Prisoner’s Dilemma in CDT
Answer: Defect, since my choice does not affect the other choice
Page: 2
Section: 1
Kind: Dilemma

Question: Psychological Twin Prisoner’s Dilemma in FDT
Answer: Cooperate, since both cooperation are better than both betrayal
Page: 2
Section: 1
Kind: Dilemma

Name: Newcomb's problem
Definition: An agent finds herself standing in front of a transparent box labeled “A” that contains $1,000, and an opaque box labeled “B” that contains either $1,000,000 or $0. A reliable predictor, who has made similar predictions in the past and been correct 99% of the time, claims to have placed $1,000,000 in box B iff she predicted that the agent would leave box A behind. The predictor has already made her prediction and left. Box B is now empty or full. Should the agent take both boxes (“two-boxing”), or only box B, leaving the transparent box containing $1,000 behind (“one-boxing”)?
Page: 3
Section: 2
Kind: Dilemma

Name: Two-boxing
Definition: Choosing two boxes in Newcomb's problem
Page: 3
Section: 2
Kind: Dilemma

Name: One-boxing
Definition: Choosing one box in Newcomb's problem
Page: 3
Section: 2
Kind: Dilemma

Question: EDT on Newcomb's problem
Answer: One box: “It would be good news to learn that I had left the $1,000 behind; for then, with 99% probability, the predictor will have filled the opaque box with $1,000,000.”
Page: 3
Section: 2
Kind: Dilemma

Question: CDT on Newcomb's problem
Answer: Two-boxing: “The predictor already made her prediction at some point in the past, and filled the boxes accordingly. Box B is sitting right in front of me! It already contains $1,000,000, or is already empty. My decisions now can’t change the past; so I should take both boxes and not throw away a free $1,000.”
Page: 3
Section: 2
Kind: Dilemma

Name: The Smoking Lesion Problem
Definition: An agent is debating whether or not to smoke. She knows that smoking is correlated with an invariably fatal variety of lung cancer, but the correlation is (in this imaginary world) entirely due to a common cause: an arterial lesion that causes those afflicted with it to love smoking and also (99% of the time) causes them to develop lung cancer. There is no direct causal link between smoking and lung cancer. Agents without this lesion contract lung cancer only 1% of the time, and an agent can neither directly observe nor control whether she suffers from the lesion. The agent gains utility equivalent to $1,000 by smoking (regardless of whether she dies soon), and gains utility equivalent to $1,000,000 if she doesn’t die of cancer. Should she smoke, or refrain?
Page: 3-4
Section: 2
Index: 3
Kind: Dilemma

Question: CDT on the Smoking Lesion Problem
Answer: Smoke
Page: 4
Section: 2
Index: 3
Kind: Dilemma

Question: EDT on the Smoking Lesion Problem
Answer: Don't smoke: “If I smoke, then that is good evidence that I have a condition that also causes lung cancer; and I would hate to learn that I have lung cancer far more than I would like to learn that I smoked. So, even though I cannot change whether I have cancer, I will select the more auspicious option.”
Page: 4
Section: 2
Index: 3
Kind: Dilemma

Question: Usual answer of CDT for two-boxing
Answer: The agent is not responsible for the fact they is punished for acting rationally
Page: 4
Section: 2

Question: Difference between Newcomb's decision maker and carcinogenic lesion ?
Answer: The decision maker consider precommitments and decision-making of the agent, the carcinogenic lesion does not
Page: 5
Section: 2

Smaller0: Newcomb's problem
Greater0: psychological twin prisoner's dilemna
Page: 5
Section: 2
Smaller to greater: is decision-theoretically isomorphic to

Question: What comportment is judged unfair ?
Answer: Deciding rewards based on the decision algorithm used.
Page: 6
Section: 2

Name: Subjunctive dependence
Definition: A dependence of agent future action
Page: 6
Section: 3

Name: Parfit’s Hitchhiker Problem
Definition: An agent is dying in the desert. A driver comes along who offers to give the agent a ride into the city, but only if the agent will agree to visit an ATM once they arrive and give the driver $1,000.
The driver will have no way to enforce this after they arrive, but she does have an extraordinary ability to detect lies with 99% accuracy. Being left to die causes the agent to lose the equivalent of $1,000,000. In the case where the agent gets to the city, should she proceed to visit the ATM and pay the driver?
Page: 8
Section: 4

Question: Answer of CDT to Parfit’s Hitchhiker Problem ?
Answer: Do not pay
Page: 8
Section: 4

Question: Answer of EDT to Parfit’s Hitchhiker Problem ?
Answer: Do not pay
Page: 8
Section: 4

Name: The Transparent Newcomb Problem
Definition: Events transpire as they do in Newcomb’s problem, except that this time both boxes are transparent—so the agent can see exactly what decision the predictor made before making her own decision.
The predictor placed $1,000,000 in box B iff she predicted that the agent would leave behind box A (which contains $1,000) upon seeing that both boxes are full. In the case where the agent faces two full boxes, should she leave the $1,000 behind?
Page: 8
Section: 4

Question: Answer of EDT to the Transparent Newcomb Problem
Answer: Takes both boxes
Page: 9
Section: 4

Question: Answer of CDT to the Transparent Newcomb Problem
Answer: Takes both boxes
Page: 9
Section: 4

Question: Answer of FDT to the Transparent Newcomb Problem
Answer: One-boxe
Page: 9
Section: 4

Smaller0: Transparent Newcomb Problem
Greater0: Parfit’s hitchhiker problem
Page: 9
Section: 4
Smaller to greater: is isomorphic to

Name: \(a\) dominate \(b\)
Definition: holding constant the rest of the world’s state, switching from \(b\) to \(a\) is sometimes better (and never worse) than sticking with \(b\).
Page: 10
Section: 4
Variables: \(a,b\) two actions

Question: Primary reason of CDT
Answer: At no time, the action chosen is dominated by another action
Page: 10
Section: 4