Yes/No Voting

Alex Small asmall at physics.ucsb.edu
Mon Dec 9 15:08:57 PST 2002

```Gervase Lam said:
> If there were just three candidates, would this be equivalent to Borda?
> Doesn't this make it more susceptible to order reversal than Approval?

Borda would force you to give 1, 0, and -1 points to your favorite,
middle, and least favorites respectively.  In Approval, you would still
want to give 1 and -1 to favorite and least favorite respectively, but you
would have 3 options for your second.  You could still give him zero if
you wanted, but you might decide that you'd prefer to give him either more
or less help.  The choice is yours.

> Also, how is this strategically equivalent to Approval?  Could you give
> some examples?

The basic idea is that if you want to help a candidate then you should
help him as much as possible by giving him the maximum score.  If you want
to hurt a candidate you should hurt him as much as possible by giving him
the minimum score.  There's then no reason to give somebody an
intermediate score, hence everybody gets either min or max, which is
equivalent to Approval.

Some people (myself included) would argue that there are situations where
it's in your best interests to give intermediate scores.  Still, I think
the above argument is a fair representation of the argument that Cardinal
Ratings is strategically equivalent to Approval.

> Personally I prefer the levels to be scored 1 (Full vote/point), 0.5
> (Half  vote/point) and 0 (No vote/points).  This would probably be
> easier for the  voter.

That's certainly equivalent to the options {-1, 0, 1}, but psychologically
there is something to be said for giving George W negative points, worse
than nothing.

Alex

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