On 24.8.2011, at 2.07, fsimm...@pcc.edu wrote:

> But back to a possible generic meaning of a score or cardinal rating:  if you 
> think that candidate X would 
> vote like you on a random issue with probability p percent, then you could 
> give candidate X a score that 
> is p percent of the way between the lowest and highest possible range values.
> 
> Note that this meaning is commensurable across the electorate.

This is the best proposal so far since this takes us as far as offering 
commensurable ratings. Maybe we should add also voter specific weights to the 
different issues.

Voters could start from the set of issues that the representative body or 
single representative covered during the last term. They could adjust those 
issues a bit to get a list of issues that are likely to emerge during the next 
term. That makes a list that is the same to all (and that makes the opinions 
therefore commensurable). Weighting makes the results more meaningful since to 
some voters some questions might be critical and others might be irrelevant. 
Without the weights the ratings might not reflect the preference order since we 
might have misbalance due to too many questions of one kind or due to questions 
of varying importance.

In principle one could collect the opinions also indirectly by generating an 
explicit list of issues and asking voters to mark their opinion an weight on 
each issue. That list could be structured or allow voters to indicate the 
importance of each group of questions. It is however not obvious how the 
questions should be grouped. Grouping could also influence the results. It 
would be also difficult to the voter to estimate the level of overlap between 
different issues. In practice one may get equally good results by simply asking 
"how much do you think you will agree with this candidate (from 100% to 0%)".

> A few years ago Jobst gave a rather definitive discussion of this issue.

That is one of the most informative and well written mails of the EM list.

> For example, if you have a choice between alternative X or a coin toss to 
> decide between Y and Z, and 
> you don't care one whit whether or not X is chosen or the the coin toss 
> decides between Y and Z, then 
> (for you)objectively X has a utility value half way between Y and Z.

The lottery approach is not as good as the issue agreement approach. The issue 
agreement approach can set clear fixed points in the scale, 100% agreement and 
0% agreement, which makes it commensurable.

The lottery approach (at least by default) also compares voter utilities, while 
the issue agreement approach need not (the utility of a 50% agreed candidate 
need not be half way between the 100% and 0% agreed candidates). Use of 
utilities makes the lottery approach non-commensurable, if we assume that 
individual utilities can not be compared as numbers in this way. Percentage of 
agreements on the other hand is more like a technical fact (has same scale for 
all voters). And one can add also personal weights to that without making it 
non-commensurable.

The proportion of agreed (weighted) issues does not give us voter utilities 
yet. Some voters might care less about the election results than some others. 
But on the other hand often we don't want to use utilities (= personal strength 
of preference) in the elections. We rather think that one (wo)man should have 
on vote. The vote of rich and poor voters should have the same weight. And in 
the same way the opinion of a voter who says "this is just my opinion" should 
maybe have the same weight as the opinion of a voter who says "do as I tell you 
to do". (Anyway, all I'm seeking here is commensurable ratings, not 
commensurability of personal utilities.)

In the agreed issues approach we thus have votes that are normalized so that 
the votes of different voters are commensurable. This is different from the 
more common normalization where the ratings of a ballot are rescaled so that 
they cover the whole scale from min to max value. The latter normalization 
depends on what kind of candidates there are, the former one does not.

Do you all agree that ratings can be commensurable? It is of course another 
question how to get those ratings for some method in a competitive election 
(and how to derive opinions of the societies from those sincere commensurable 
ratings).

Note btw also that if we want the outcome to be the utility of each candidate 
to the society (and elect the one with highest utility), it is not necessary to 
derive those utilities from the utilities of individual voters. We might as 
well take a shortcut and derive the society utility from something else, like 
the issue agreement values.

Juho




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