= 27d567bc2d48d9f40e9ccc20ea370b15)
steven0461 comments on Dissenting Views - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (207)
Huh? A utility function is a map from states/gambles/whatever to real numbers that respects preferences. A prior is a probability assigned without conditioning on evidence. Maybe some terms people use here are for showing off, but these two happen to be clear and useful.
A prior is a probability distribution assigned prior to conditioning on some specific data. If I learn data1 today and data2 tomorrow, my overnight probability distribution is a posterior relative to data1 and a prior relative to data2.
The reason I nitpick this is because the priors we actually talk about here on LW condition on massive amounts of evidence.
More nitpicking: the data doesn't really have to be "specified" - at least, it can be presented in the form of a black box with contents that are not yet known, or perhaps not yet even measured.
That's not its only meaning. It's not, for example the definition that a hedonist utilitarian would give (net pleasure-over-pain is not equivalent to preference; unless you're giving preference a very broad interpretation, in which case you've just shifted the ambiguity back a level.)
I've seen that called "utility" but never a "utility function".
I could go trawling through the literature to get you examples of non-preferentist usages of the words "utility function", but if you're willing to take my word for it, I can assure you that they're pretty common (especially in happiness economics and pre-ordinalist economics, but also quite broadly apart from that). Indeed, it would be very strange if e.g. the hedonist account were a valid definition of utility, but no-one had thought to describe a mapping from states of the world into hedonist-utility as a utility function.
Googling "experienced utility function" turns up a few examples, but there are many more.
Guess I'll take your word for it. Not sure I remember seeing that usage for "utility function" on LW, though.
ETA: It gets kind of confusing, because if I prefer that people are happy, their happiness becomes my utility, but in a way that doesn't contradict utility functions as a description of preferences.
Many uses are ambiguous enough to encompass either definition. If you aren't aware of the possible ambiguity then you're unlikely to notice anything awry - at least up until the point where you run into someone who's using a different default definition, and things start to get messy. (This has happened to me a couple of times.)
I've argued that utilitarians should probably employ surreal-valued utilitiy functions. However, that is hardly a major disagreement. It would be like the creationists arguing that evolution was a theory mired in controversy because of the "puctuated equilibrium" debate.