At 04:41 PM 1/21/2010, Jonathan Lundell wrote:
On Jan 21, 2010, at 1:32 PM, Kathy Dopp wrote:
> Terry, You cleverly conveniently change all the definitions whenver it
> is necessary to make yourself and Fairytale Vote right on the "facts".
Define "spoiler", please, unambiguously.
The term has usage, and must be understood from that. A formal
definition, nailing it down, would be arbitrary. But Kathy's
definition is one reasonable one that matches common usage.
But there is another which is broader and, to distinguish this from
the common usage, I call the common usage the "first order spoiler
effect." It refers to minor candidates, with hopelessly low support,
who alter the outcome between two major candidates by drawing away
votes preferentially from one, from voters who would otherwise vote
for that one. The application most common is with plurality, but also
top-two runoff and, similarly, IRV, where as little as one vote and
some back luck in the resolution of a tie can cause the effect.
To define this l.e. spoiler effect more crisply would be arbitrary.
But then there is a more generalized "spoiler effect," more commonly
referred to as center squeeze. It's a spoiler effect, all right, in
substance, because an extremist candidates, who would lose in a
direct contest between either the centrist or the other extremist,
draws enough higher preference votes away from the centrist to reduce
that centrist below second rank in first preference. So this is an IIA problem.
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