[EM] Simulation of Duverger's Law

[Raph Frank]

On Thu, Oct 16, 2008 at 6:46 AM, Greg Nisbet <gregory.nisbet at gmail.com> wrote:
> Why doesn't France's Two Round System lead to the same result?

It could be argued that the first round is somewhat random.  Also,
parties can combine temporarily without formally combining.

> Pretend you
> have a ballot consisting of rank ordering and a separate FPTP checkbox,
> would this similarly avoid two party domination?

I assume you mean that you simulate top 2 runoff.  The top 2 plurality
winners are then 'run-off' using the ranked ballots.  This is
sometimes called instant top 2 runoff.  I think some postal ballots,
in some State with top 2 runoff, work that way.

One disadvantage is that the campaign between the top 2 never happens.
 This gives voters the abiltity to make a better decision between the
top 2.