[EM] Letter to Discover Magazine

[Bart Ingles]

Dear Editor:

Dana Mackenzie's article [May the Best Man Lose, November] may be the
best treatment of the subject I have seen in a popular publication.  Of
the featured voting systems, Borda could well be the method of choice
for engineering applications where the voters are automata incapable of
varying preference levels.

Not so with human voters.  Suppose the voters rate candidates on a scale
of 0-10 (ratings in parentheses):

45%   Clinton(10)   Perot(1)   Bush(0)
25%   Perot(10)     Bush(1)    Clinton(0)
30%   Bush(10)      Perot(1)   Clinton(0)  

Here Perot is the Borda winner, even though 75% of voters strongly
dislike Perot.  The runoff winner (Bush) is despised by 70%, while the
plurality winner is only rejected by 55% (and seems the best choice in
this example).

Of course, if either Bush or Perot were more highly rated as a second
choice, then Runoff or Borda would choose the better winner.  No
deterministic voting system can be correct in all cases where the voters
are either strongly for or strongly against each candidate.

Approval voting does adapt to all of these scenarios, if we assume the
voters are rational and willing to make modest compromises in exchange
for large gains in probable outcome.  To me it seems more important for
a system to behave reliably in such highly polarized situations, than to
worry about which solution is best when the voters themselves are
ambivalent.

Bart Ingles, Jr.