conchis comments on Utilons vs. Hedons - Less Wrong

28 Post author: Psychohistorian 10 August 2009 07:20PM

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Comment author: conchis 11 August 2009 02:23:13PM *  2 points [-]

If you accept that you're maximizing expected utility, then you should draw the first card, and all future cards. It doesn't matter what terms your utility function includes.

Note however, that there is no particular reason that one needs to maximise expected utilons.

The standard axioms for choice under uncertainty imply only that consistent choices over gambles can be represented as maximizing the expectation of some function that maps world histories into the reals. This function is conventionally called a utility function. However, if (as here) you already have another function that maps world histories into the reals, and happen to have called this a utility function as well, this does not imply that your two utility functions (which you've derived in completely different ways and for completely different purposes) need to be the same function. In general (and as I've I've tried, with varying degrees of success to point out elsewhere) the utility function describing your choices over gambles can be any positive monotonic transform of the latter, and you will still comply with the Savage-vNM-Marschak axioms.

All of which is to say that you don't actually have to draw the first card if you are sufficiently risk averse over utilons (at least as I understand Psychohistorian to have defined the term).

Comment author: DanArmak 11 August 2009 02:49:35PM 0 points [-]

Thanks! You're the first person who's started to explain to me what "utilons" are actually supposed to be under a rigorous definition and incidentally why people sometimes seem to be using slightly different definitions in these discussions.

consistent choices over gambles

How is consistency defined here?

Comment author: Vladimir_Nesov 11 August 2009 03:01:36PM 1 point [-]

You can learn more from e.g. the following lecture notes:

B. L. Slantchev (2008). `Game Theory: Preferences and Expected Utility'. (PDF)

Comment author: conchis 11 August 2009 03:58:04PM 0 points [-]

How is consistency defined here?

Briefly, as requiring completeness, transitivity, continuity, and (more controversially) independence. Vladimir's link looks good, so check that for the details.

Comment author: DanArmak 11 August 2009 04:03:05PM 0 points [-]

I will when I have time tomorrow, thanks.