#jonomancer

how do you feel about rabbits

Rabbit/girl image:

Like, their probability for “Obama is a secret Muslim” starts at 0.00001 and when Obama makes a conciliatory gesture towards Iran they go “Hmm, a secret Muslim would do that with probability 0.99, a non-Muslim democratic president would do that with probability 0.87, better update Obama-is-a-Muslim to 0.000012.” And don’t I also need probabilities for “Obama is a werewolf” and “Obama likes ice cream” and in fact *every possible declarative English sentence* i can write about Obama? (cont)

Even if I pick a finite subset to focus on, how the hell do I estimate the conditional probabilities? Aren’t I just pulling 2 numbers out of my ass to “update” the accuracy of another number I pulled out of my ass? When an LW-er says “I’m updating my probability for X” are they literally estimating conditionals or is it just a jargony way of saying “oh hey i hadn’t considered that angle”? In which case, does Bayesianism really mean anything more precise than “try to be open to new evidence”?

I don’t know of anyone who’s actually done anything like this.

However, there are LWers who make bets in prediction markets, which (among other things) can be seen as a way of definitively committing to specific probabilities in somewhat the way you describe.  E.g. here are the bets made on predictionbook.com by prominent LW guy gwern

I think the standard LW answer to the questions in your last paragraph would be “ideally one would literally do the spreadsheet thing, but of course one can’t do that in real life.  But keeping that in mind as an ideal can lead to various rules of thumb for thinking.  ’Try to be open to new evidence’ is one, but not the only one.”  (hot-gay-rationalist has a post here about this kind of thing.)

It’s kind of similar to how some of the early utilitarians hoped that giant unwieldly computations about utility could eventually be boiled down to some simple rules, so that you’d be able to “derive” the “right” simple practical morality by writing some 1000-page treatise on utility or whatever, and then go around living by that simple practical morality in real life, rather than thinking about utility all the time.

Jonomancer drew adorable pics of himself as a girl, so naturally I needed to respond with what we'd be like as a genderswapped couple.  <3  (Genderswapped me previously seen here)

In the process I was able to remind him that girls have way more awesome socks, and he decided that he would probably shave his legs.  :D