Basil Halperin

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Newcomb’s problem is just a standard time consistency problem

basilhalperin.substack.com

Newcomb’s problem is just a standard time consistency problem

Basil Halperin
Mar 31, 2022
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Newcomb’s problem is just a standard time consistency problem

basilhalperin.substack.com

https://www.basilhalperin.com/essays/newcomb.html

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Basil Halperin @BasilHalperin
Newcomb’s problem is just a standard time consistency problem basilhalperin.com/essays/newcomb… I argue the typical description of Newcomb’s problem is confusing only because it unintentionally conflates *two different possible points in time* from which you could make your choice
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5:07 PM ∙ Mar 31, 2022
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Basil Halperin @BasilHalperin
Split into the two possible cases, Newcomb’s problem is basically trivial – and doesn’t require revising decision theory! In fact, the problem is (literally) isomorphic to the canonical Kydland-Prescott (1978) central bank time consistency problem from macroeconomics
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5:07 PM ∙ Mar 31, 2022
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Basil Halperin @BasilHalperin
Steelmanning the opposing view: I think folks who argue Newcomb demonstrates a flaw in standard decision theory are implicitly arguing (and should *explicitly* argue!), “We want to come up with a decision theory that never encounters time consistency problems”
5:07 PM ∙ Mar 31, 2022
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Basil Halperin @BasilHalperin
“We want to come up with a decision theory that never encounters time consistency problems” Honestly I think that’s just a fool’s errand. It’s like trying to come up with a decision theory that never encounters multiple equilibria. Sorry, that’s just a thing that happens
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5:07 PM ∙ Mar 31, 2022
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Basil Halperin @BasilHalperin
Nerds in this literature should also note that the notion of “program equilibrium”, sometimes used in this lit, is implicitly smuggling a notion of commitment in – hence why it gives the “updateless” answer (Same with the “contractible contracts” of Peters and Szentes 2012)
5:07 PM ∙ Mar 31, 2022
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Newcomb’s problem is just a standard time consistency problem

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