Letter Published in the Financial Times

FINANCIAL TIMES Thursday April 28, 2011

       Alternative vote is unfair to third parties and voters

From Dr. John Howard Wilhelm

Sir, For one who has studied the technical literature on voting systems
for the last decade and a half, your editorial "A better choice of voting
system" (April 26) supporting the alternative vote comes as a
personal disappointment.  As Professor Steven Brams of New York
University has pointed out there is a science of voting.  If you look
at that literature, including your own Sir Michael Dummett's very fine
book "Principles of Electoral Reform" (Oxford University Press, 1997),
it is very clear that claims as to the advantage of the AV turn out on
critical examination simply to be bogus.  Unfortunately, the claims in
your April 26 leader suffer the same defect, especially on two
important matters: fairness towards third parties and fairness towards
the voters.

First, it is doubtful in the extreme that AV is really more
sympathetic to small parties.  Like FPTP, AV tends to drive voters
towards two big parties and under-rewards third parties for the
support they win.  Second, under the alternative vote--instant runoff
voting ( IRV) in American parlance-- a shift in public opinion toward
a candidate can cause the candidate to lose, and a shift away from a
candidate can cause the candidate to win!  Many supporters of AV
assert that such cases are very rare--perhaps once in a century.
Unfortunately, the evidence does not support this. Of the two AV, or
IRV, elections I know about in the US in 2009, both evidenced this
pathology (Burlington, VT and Aspen, CO).  And recently it was brought
to my attention that the same occurred in a by-election in Australia
in the same year.

Work done by Professor Robert Norman and Joe Ornstein at Dartmouth
College suggests that this pathology can occur in up to a fifth of
elections in close contests.  You could achieve the same results with
FPTP by simply mandating vote stealing in a fifth of the contests in
close elections; you don't need to institute AV to do this, though
that would clearly be the consequences of a yes vote on May 5.

John Howard Wilhelm,
Ann Arbor, MI, US