'Decision-theoretic paradoxes as voting paradoxes'

Whoa, no. That's a bad mantra. Wireheading, quantum immortality, doing meth - these are bad things.

Briggs is here primarily considering cases where your preferences don't change as a result of your decision (but where your credences might). If we're interested in criticising the argument precisely as stated then perhaps this is a reasonable criticism but it's not an interesting criticism of Briggs' view which is to do with how we reason in cases where our decision gives us new information about the state of the world (ie. about changing credences not ch... (Read more)(Click to expand thread. ⌘/CTRL+F to Expand All)Cmd/Ctrl F to expand all comments on this post

This isn't true with Briggs' argument - it can't simply be resolved by having cardinal preferences.

Yup, I missed that a year ago.

evil-CDT

I'm not sure where I was going with that either.

Briggs is here primarily considering cases where your preferences don't change as a result of your decision (but where your credences might).

True. Though on the other hand, the smoking lesion problem (and variants) is pretty much the credence-changing equivalent of doing meth :P I still think the requirements are akin to "let's find a decision theory that does meth but never has anything bad happen to it."

'Decision-theoretic paradoxes as voting paradoxes'

by lukeprog 1 min read13th Sep 201112 comments

5


Briggs (2010) may be of interest to LWers. Opening:

It is a platitude among decision theorists that agents should choose their actions so as to maximize expected value. But exactly how to define expected value is contentious. Evidential decision theory (henceforth EDT), causal decision theory (henceforth CDT), and a theory proposed by Ralph Wedgwood that I will call benchmark theory (BT) all advise agents to maximize different types of expected value. Consequently, their verdicts sometimes conflict. In certain famous cases of conflict — medical Newcomb problems — CDT and BT seem to get things right, while EDT seems to get things wrong. In other cases of conflict, including some recent examples suggested by Egan 2007, EDT and BT seem to get things right, while CDT seems to get things wrong. In still other cases, EDT and CDT seem to get things right, while BT gets things wrong.

It’s no accident, I claim, that all three decision theories are subject to counterexamples. Decision rules can be reinterpreted as voting rules, where the voters are the agent’s possible future selves. The problematic examples have the structure of voting paradoxes. Just as voting paradoxes show that no voting rule can do everything we want, decision-theoretic paradoxes show that no decision rule can do everything we want. Luckily, the so-called “tickle defense” establishes that EDT, CDT, and BT will do everything we want in a wide range of situations. Most decision situations, I argue, are analogues of voting situations in which the voters unanimously adopt the same set of preferences. In such situations, all plausible voting rules and all plausible decision rules agree.