Instant Runoff = two party system? (was RE: Ballot Access laws f

[Steve Eppley]

Marcus Ganley wrote:
> Although it seldom occurs multiple nominations (known as 
> 'pre-selections') have occurred.  The Queensland Liberals Party 
> 'pre-selected' two candidates in Pine Rivers at, I think (Tom can 
> probably correct) the 1989 State Election.  However such is the 
> reluctance to do so that the Liberal and National parties try to 
> avoid competing in the one seat
-snip-

That's the "spoiler" dilemma, the flip side of the "lesser of
evils voting" dilemma, in action.

Marcus' info appears to confirm that CV&D and Rob Ritchie are wrong
when they declare Instant Runoff eliminates the lesser evil dilemma.

Is Australia happy with this "two-party system" method?  Is the
tallying by hand the decisive factor in continuing with Instant
Runoff rather than switching to Condorcet? 

In the U.S., we don't let the parties "pre-select" their nominees
anymore--we have open primary elections to winnow the field of
contenders to one candidate per party.  With Instant Runoff used in 
the general election, parties will still want to use primaries to 
winnow the field.  Instant Runoff in the primaries, particularly in 
the Presidential primaries where a lot of people want to contend, 
will be amusing ;-( to watch.

What voting method is used within the Australian parliament?  Do they 
tally the legislators' preference orders, or use an amendment agenda 
to compare choices two at a time?  If there was any validity to 
Instant Runoff, one would expect it to be useful in parliament, where 
picking one of a large set of conflicting alternatives must happen 
all the time.

---Steve     (Steve Eppley    seppley at alumni.caltech.edu)