[EM] Chris: Approval vs IRV

[MIKE OSSIPOFF]

Chris--

I'd said:

>Actually, IRV is at its very worst when people vote sincerely. Often the CW 
>can be saved only be the extreme insincere strategy of favorite-burial.

You replied:

At least IRV has some appearance of TRYING to meet this standard.
"Electing the CW" is far from the only interpretation  of "performing 
reasonably".

I reply:

But voters have shown that they'll do what it takes to elect the CW. Most 
people's voting strategy here, though based on completely false information, 
is intended to maximize the voter's utility expectation or to elect the CW. 
That's evident from what people say, though they don't mention utility 
expectation or CW. Riker demonstrated that if voters want to optimize the 
outcome for themselves, and have complete information about eachother's 
preferences,  then the CW wll win. I don't know exactly what his assumptions 
were, but it might have involved repeated elections, converrging on the CW 
if one exists.

So a method that requires favorite-burial to elect the CW is going to make 
people bury their favorite.
That's what I & others object to about IRV.

You continued:

As Marcus S.
has explained to you before: "The aim of IRV is not to elect the sincere 
Condorcet winner. The
aim of IRV is to elect the sincere IRV winner."

I reply:

Every method does a perfect job of electing its own winner. The fact that 
IRV is good at electing its own winner can't be counted as an accomplishment 
of IRV.

And, because of the drastically insincere strategy (favorite-burial) that 
IRV will often require, IRV can't be said to be good at electing the sincere 
IRV winner. The sincere IRV winner will often be an extreme candidate far 
from the voter median, and the election of the sincere IRV winner could then 
be very bad news.

I'd said:

>Like when, in IRV, the election of a CW depends on voters insincerely 
>voting the CW in 1st place, over their genuine favorite?

CB: In Australia and doubtless many other countries, almost none of the 
voters have a concept of the
"CW"

I reply:

No, but that doesn't mean that they won't do what they can to elect the CW, 
though they've never heard the term. Or strategize to maximize their utility 
expectation, though they haven't heard of that either.

The CW tends to be the best compromise that you can get, if you need a 
compromise.

For instance, here, this year, many who prefer Nader to Kerry have been 
convinced by their tv that only Kerry can beat Bush. They believe that if 
all the people preferring Nader to Bush voted for Nader, there's a greater 
number preferring Bush to Nader who would vote for Bush, and Bush would win.

In other words, they believe  that Bush is preferred to Nader by more people 
than prefer Nader to Bush. But they believe that more prefer Kerry to Bush 
than Bush to Kerry, and it's probably true, for what it's worth. So, as they 
believe it, Bush has a pairwise win against Nader, but Kerry has a pairwise 
win against Bush.

Anyone with a sincere pairwise win against Bush is what they're looking for, 
and they know that if X has a sincere pairwise win against Y, and if 
everyone who has that preference votes for X in Plurality, Y loses. They 
don't call Bush the CW, but what they're going by differs only in wording. 
They're using the drasrtic defensive strategy of favorite-burial to elect 
whom they believe to be the CW, based on false information.

Sometimes they'll have to do the same thing in IRV.

And before you say that IRV works fine elsewhere, I point out that here 
isn't elsewhere. Political systems, voters, candidates differ.

Recorded data don't contain the information needed to tell us whether CWs 
are being eliminated in IRV in current use.