[EM] voter strategy & 2-party domination under IRV voting

[Scott Ritchie]

On Fri, 2005-08-19 at 15:46 +0100, James Gilmour wrote:
> Juho Laatu  Sent: Friday, August 19, 2005 7:32 AM
> > 
> > I continued the chain of thoughts a bit.
> > I must add one item in my list of good sides of two-party systems. That 
> > is the fact that there will be a change, and the change will be considerable. ;-) 
> 
> I would add several important caveats here.  A two-party system is OK if it fairly represents the wishes of the
> electors.  In Malta they now have a very strict two-party system and we know that's what the electors want because the
> Maltese Parliament is elected by STV-PR.  When STV was first introduced (1921) more parties did get significant support,
> but over the years the VOTERS have changed the system from multi-party to two-party.  The problem in the UK (and in many
> other countries and states) is that a two-party system is the result of a defective voting system (usually FPTP in
> single-member districts  -  as a British legacy!) that does not at all fairly reflect the wishes of the voters.
> 

I believe the Maltese movement towards two parties is an artifact of the
Maltese version of STV.  Due to the Maltese systems method of granting
bonus seats based on the top-choice ranking of candidates, the Maltese
system is really a lot more like an open list PR system with the voter's
indicated first preference acting as their party tick.

This strange rule leads to a partisan strategy of trying to win more
first tick votes on a party basis in an attempt to hedge bets on the
bonus seats, granting a significant bonus to partisan grouping not
present in typical STV systems.  This is important, as in Malta it is
not nearly as profitable to run as an independent or minor party
candidate as you then lose your chance of getting into the government
anyway on a bonus seat, which requires being a loyal party member to do
- leading to a strong force against third parties.


By the way, check out the section on Malta at the newly featured article
on STV at Wikipedia:
http://en.wikipedia.org/wiki/Single_Transferable_Vote 

> My point was not that "STV style systems do not exclude parties", but rather that parties are not less apparent and no
> less active where STV-PR is used for public elections.  In Malta, STV functions like a very strict party system, but
> with the important difference that all the elected members are the candidates chosen for their personal support among
> the voters.  In Ireland, there is a great deal of cross-party voting as the voters give a high priority to features
> other than party membership when deciding who will best represent them.
> 

Note that Ireland has significantly smaller districts than Malta -
somewhere between 3 and 5 candidates in Ireland, and frequently much
more in Malta.  Yet, Ireland has less reliance on parties, despite being
less able to represent smaller parties due to the smaller voting
districts.

Cheers,
Scott Ritchie