Func­tional De­ci­sion Theory

TagLast edit: 17 Nov 2022 5:31 UTC by Roman Leventov

Functional Decision Theory is a decision theory described by Eliezer Yudkowsky and Nate Soares which says that agents should treat one’s decision as the output of a fixed mathematical function that answers the question, “Which output of this very function would yield the best outcome?”. It is a replacement of Timeless Decision Theory, and it outperforms other decision theories such as Causal Decision Theory (CDT) and Evidential Decision Theory (EDT). For example, it does better than CDT on Newcomb’s Problem, better than EDT on the smoking lesion problem, and better than both in Parfit’s hitchhiker problem.

In Newcomb’s Problem, an FDT agent reasons that Omega must have used some kind of model of her decision procedure in order to make an accurate prediction of her behavior. Omega’s model and the agent are therefore both calculating the same function (the agent’s decision procedure): they are subjunctively dependent on that function. Given perfect prediction by Omega, there are therefore only two outcomes in Newcomb’s Problem: either the agent one-boxes and Omega predicted it (because its model also one-boxed), or the agent two-boxes and Omega predicted that. Because one-boxing then results in a million and two-boxing only in a thousand dollars, the FDT agent one-boxes.

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See Also:

Func­tional De­ci­sion The­ory: A New The­ory of In­stru­men­tal Rationality

ESRogs20 Oct 2017 8:09 UTC
16 points
1 comment1 min readLW link

Let’s Dis­cuss Func­tional De­ci­sion Theory

Chris_Leong23 Jul 2018 7:24 UTC
29 points
18 comments1 min readLW link

De­con­fus­ing Log­i­cal Counterfactuals

Chris_Leong30 Jan 2019 15:13 UTC
27 points
16 comments11 min readLW link

A Cri­tique of Func­tional De­ci­sion Theory

wdmacaskill13 Sep 2019 19:23 UTC
82 points
56 comments20 min readLW link

Dis­solv­ing Con­fu­sion around Func­tional De­ci­sion Theory

scasper5 Jan 2020 6:38 UTC
31 points
26 comments9 min readLW link

AXRP Epi­sode 5 - In­fra-Bayesi­anism with Vanessa Kosoy

DanielFilan10 Mar 2021 4:30 UTC
33 points
12 comments35 min readLW link

Violent Un­rav­el­ing: Suici­dal Majoritarianism

mako yass29 Jul 2021 9:29 UTC
6 points
4 comments2 min readLW link

MIRI/​OP ex­change about de­ci­sion theory

Rob Bensinger25 Aug 2021 22:44 UTC
49 points
7 comments10 min readLW link

A Defense of Func­tional De­ci­sion Theory

Heighn12 Nov 2021 20:59 UTC
23 points
223 comments10 min readLW link

A Re­ac­tion to Wolf­gang Sch­warz’s “On Func­tional De­ci­sion The­ory”

Heighn5 Jan 2022 9:00 UTC
5 points
9 comments7 min readLW link

Cri­tiquing Scasper’s Defi­ni­tion of Sub­junc­tive Dependence

Heighn10 Jan 2022 16:22 UTC
6 points
8 comments2 min readLW link

Defend­ing Func­tional De­ci­sion Theory

Heighn8 Feb 2022 14:58 UTC
4 points
10 comments11 min readLW link

An In­tu­itive In­tro­duc­tion to Func­tional De­ci­sion Theory

Heighn7 Mar 2022 16:07 UTC
21 points
2 comments7 min readLW link

Alex Tabar­rok ad­vo­cates for crowd­fund­ing sys­tems with *Re­fund Bonuses*. I think this might be a nat­u­ral oc­cur­rence of a money pump against Causal De­ci­sion The­ory pledgers

mako yass14 Mar 2022 7:27 UTC
16 points
13 comments1 min readLW link

No, EDT Did Not Get It Right All Along: Why the Coin Flip Creation Prob­lem Is Irrelevant

Heighn30 Mar 2022 18:41 UTC
6 points
6 comments3 min readLW link

[Question] What does Func­tional De­ci­sion The­ory say to do in im­perfect New­comb situ­a­tions?

Daniel_Eth7 May 2022 22:26 UTC
4 points
4 comments1 min readLW link

[Question] Al­gorith­mic for­mal­iza­tion of FDT?

shminux8 May 2022 1:36 UTC
12 points
8 comments1 min readLW link

New­comb­ness of the Din­ing Philoso­phers Problem

Nathan11236 Aug 2022 21:58 UTC
10 points
2 comments2 min readLW link

Log­i­cal coun­ter­fac­tu­als are brit­tle; use conditionals

Sylvester Kollin15 Sep 2022 8:55 UTC
20 points
1 comment16 min readLW link

FDT is not di­rectly com­pa­rable to CDT and EDT

Sylvester Kollin29 Sep 2022 14:42 UTC
29 points
7 comments11 min readLW link

You’re Not One “You”—How De­ci­sion The­o­ries Are Talk­ing Past Each Other

keith_wynroe9 Jan 2023 1:21 UTC
26 points
11 comments8 min readLW link

Quan­tum Suicide, De­ci­sion The­ory, and The Multiverse

Slimepriestess22 Jan 2023 8:44 UTC
4 points
38 comments10 min readLW link

Threat­en­ing to do the im­pos­si­ble: A solu­tion to spu­ri­ous coun­ter­fac­tu­als for func­tional de­ci­sion the­ory via proof theory

Christopher King11 Feb 2023 7:57 UTC
5 points
4 comments5 min readLW link
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