[EM] Why I think IRV isn't a serious alternative 2

[Abd ul-Rahman Lomax]

At 07:23 PM 12/22/2008, Dave Ketchum wrote:
>Disturbing that you would consider clear wins by a majority to be 
>objectionable.
>
>In Election 2 Condorcet awarded the win to M.  Who has any business objecting?
>      52 of 100 prefer M over D
>      53 of 100 prefer M over R
>      Neither R nor D got a majority of the votes.
>
>As to my  "no first preferences" example, surest way to cause such 
>is to be unable to respond to them.

I'll go both ways on this. The election outcome as stated is close, 
not an obvious one. It's obvious when there are many small parties, 
as in France in 2000. The Condorcet winner, almost certainly, was in 
third place, just a nose behind the second place. In this particular 
example, IRV would probably have transferred sufficient votes to 
Jospin to keep him in to the last round, where he would have won. But 
with a less fanatic candidate than Le Pen, it's not at all 
guaranteed, and in a two-party system, with occasional candidacies 
that contest that, it is likewise very possible.

There are two reasons why Top Two Runoff might have different results 
than IRV; the first is that different voters show up, and the second 
is that voters change their minds. Both of these phenomena favor 
candidates preferred with strong preferences. Whatever the reason, it 
clearly happens, about one out of three TT Runoffs. Very rarely -- no 
examples in the U.S. so far for nonpartisan elections (almost all of 
these elections are nonpartisan; partisan elections show different 
phenomena, and "comeback" elections do happen.)

The scenario where a Condorcet winner has only 5% of first 
preferences would require two competing candidates both squeezing the 
center, so that primary support for the center is weak, even though 
overall pairwise preference may be strong, in comparison to the other 
two candidates. It also depends on the distribution of preferences.

But a Condorcet winner is unlikely to be viewed as illegitimate. It's 
the reverse that will suffer this problem, in some cases. In other 
cases the electorate is mostly apathetic....