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drethelin comments on Against utility functions - Less Wrong Discussion

40 Post author: Qiaochu_Yuan 19 June 2014 05:56AM

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Comment author: evec 22 June 2014 09:03:03PM 2 points [-]

Sure. Say you have to make some decision now, and you will be asked to make a decision later about something else. Your decision later may depend on your decision now as well as part of the world that you don't control, and you may learn new information from the world in the meantime. Then the usual way of rolling all of that up into a single decision now is that you make your current decision as well as a decision about how you would act in the future for all possible changes in the world and possible information gained.

This is vaguely analogous to how you can curry a function of multiple arguments. Taking one argument X and returning (a function of one argument Y that returns Z) is equivalent to taking two arguments X and Y and returning X.

There's potentially a huge computational complexity blowup here, which is why I stressed mathematical equivalence in my posts.

Comment author: Qiaochu_Yuan 22 June 2014 09:12:08PM 2 points [-]

Thanks for the explanation! It seems pretty clear to me that humans don't even approximately do this, though.

Comment author: jsteinhardt 24 June 2014 03:57:15PM 1 point [-]

Then the usual way of rolling all of that up into a single decision now is that you make your current decision as well as a decision about how you would act in the future for all possible changes in the world and possible information gained.

Sounds not very feasible...