Margins -- Blake is right

[Hugh R. Tobin]

Blake, 
I appreciate your very lucid treatment of the margins / votes-against
issue, and I agree with most of what you have written.
I think it is important to consider the individual voter who lacks
knowledge of the votes of others; to have a system that accurately
reflects his or her intent if he or she votes only true preferences; and
not to require sophisticated tactical voting in order for a ballot to
carry full weight for the voter's preferred candidate.  Moreover, there
is a risk that if the insincere full ballot (with random selections)
becomes the norm, outcomes in close races will be determined by random
deviations from the mean among the insincere selections.  This is a
particular risk in local elections for nonpartisan offices, where there
may be many candidates about whom voters know little, and where there is
no one-dimensional political spectrum.  Worse, the insincere votes may
not in fact be random, but based on arbitrary factors such as which name
sounds better between two unknowns (such voting already occurs; we do
not need to encourage more).

I agree with your view that for purposes of determining the significance
of a pairwise contest, the sensible use of "majority" is to refer to
more than 50% of those voting in that contest.  To use the total number
who vote in any pairwise race for the same office as the denominator to
determine whether the pairwise victory or defeat has some special
significance seems arbitrary.

I agree that votes-against does not permit a rational "defensive"
strategy of truncation; moreover I remain to be convinced that in
margins  it would ever be rational for a voter to truncate, but not to
reverse order.  (I refer to what is rational for the voter in the booth
trying to affect the outcome of the election and knowing that all votes
of others are independent of his choice, not what some candidate would
like to be able to announce that his followers will all do in lock-step
notwithstanding their own preferences and interests).

I do think there is an argument, not yet made, for a modified form of
votes-against that avoids the incentive to insincere truncation; more on
that later.  For now I wanted you to know that at least one ordinary
voter is following your arguments on this list.

-- Hugh Tobin