Re: copying related probability question

Eliezer S. Yudkowsky (
Mon, 22 Sep 1997 21:34:21 -0500

Wei Dai wrote:
> 1. If the subject's answer to question 3 is a3, then he should be willing
> to accept the following bet after giving his answer: if the coin landed
> up, he loses 1/a3 dollars, else he wins 1/(1-a3) dollars. But if a3<1/2,
> the experimenter has a positive expected profit from running the
> experiment.

You know, I remember a similar argument about what happens when you roll a
pair of dice. By playing with the number of subjects, you could have the
experimenter making a profit on 10:1 odds that a pair of dice would come up
double-sixes. The chance that a die turns double-sixes is still 1:36.

I'm still trying to work out how that applies to your argument. I think we
may need to define a few terms more carefully, like "subject".

--       Eliezer S. Yudkowsky

Disclaimer:  Unless otherwise specified, I'm not telling you
everything I think I know.