[PairTheBoard]

Did you read Tom Crowley's analysis on the original thread? He points out that the fattening of the Yes percent may be due to the G group overestimating the correct Price say of 67% for a No answer. As you go up the scale from G to A, if the distribution doesn't tighten much, you will see the tail of the distribution move down into the Yes area while the mean moves accurately downward and closer to the correct 67% Price for No.

If better evidence evaluators were available you would eventually see the spread of the distribution tighten up, and the tail in the Yes area disappear as opinion converged on a 67% Price for No. The percent of people actually answering No would then concurrently rise back up to 100%.

So your extrapolation idea is simply unsound even under the kind of assumptions you want to make. I suppose you might speculate on the relative sizes of classes of propositions for which G's overestimate and underestimate the correct price, but that seems pretty futile to me.

PairTheBoard