[EM] STV: who could ask for anything more?

James Gilmour jgilmour at globalnet.co.uk
Sun Jul 13 11:16:04 PDT 2003

I agree with much that James G-A wrote, but would add some observations.

James Green-Armytage wrote (in part): 
> 	Personally, I wouldn't lump STV and party list together 
> on the same
> level. I would argue that STV is a real leap forward from 
> party list in a
> number of ways.

I would go much further:  STV-PR and Party List PR are fundamentally
different - they have quite different objectives (as I've set out in
earlier posts to this list).

> 	For one thing, there is the fact that many countries 
> use a 'closed' list,
> which means that parties determine the order of the list rather than
> voters. For any reasonably popular party, the first couple 
> candidates on
> the list are pretty much assured to gets seats no matter how 
> things go on
> election day, and I am among the people who think that this is screwy.
> (One thing that has been said in defense of closed lists is 
> that sometimes
> women and minorities do better in closed list systems than open lists.
> This is worth consideration, but I think that there are 
> better ways for
> women and minorities to gain office that don't have the same 
> drawbacks in
> terms of accountability.)

You should be aware that the "gender balance" campaigners in Europe
(including those active in the UK) want closed, national party lists
with compulsory 'zipping', ie man/woman/man/woman/etc or
woman/man/woman/man/etc.  This is undoubtedly the most effective way to
secure the election of equal numbers of men and women, but to me it is a
complete denial of democracy.  The voters should be free to choose their
representatives.  Zipping is, of course, almost completely unworkable
for more than one "balancing" factor.


> 	Also, I am still a little bit uneasy about how party list really
> reinforces the whole sense of party identity and party unity. 

All party list systems, including MMP (= AMS in UK), reinforce and
entrench the power of the parties.

> 	Actually, that has always seemed to me to be a fatal 
> flaw in the Mixed
> Member Proportional (MMP) system, which is otherwise somewhat 
> attractive:
> it basically seems to assume that members of the same party 
> are roughly
> interchangeable. 

In a countries like the UK and New Zealand, with a strong tradition of
"constituency representation", the election of two different kinds of
member is prescription for trouble.  We saw that with MMP in New Zealand
and we have seen in Scotland where AMS is used to elect the Scottish

> 	One weird ramification of MMP is this: If you were 
> allied to a party, but
> you were allowed to run as an independent, and you think you would win
> your district anyway, then as I see it, it would be in the interest of
> your party for you to run as an independent, then just vote 
> with them all
> the time anyway once you got into office. That is, if you ran as an
> independent, then when the extra members were added to assure party
> proportionality, it would register your (undeclared) party as 
> having one
> less member, and hence they might stand to gain an extra compensatory
> seat...

In the UK implementation of AMS=MMP, the potential for "creative
distortion" is much greater.  In the Glasgow electoral region the Labour
Party will (always) win all 10 of the constituency seats for 31% of the
votes.  As there are only 17 seats in the region (10 constituency seats
plus 7 additional members) the Labour Party with 10 seats (59%) already
has more than its fair share, so there is no point in any of its
supporters voting Labour on the region ballot paper.  (Most of them do,
but that's another story.)  The Co-operative Party is a separate party
from the Labour Party, but shares most of its political objectives.  So
the Co-operative Party could nominate candidates for the regional list
and get Labour supporters all to vote Co-operative with their second
(regional) vote.  That way the Labour voters would get two real bites at
the cherry and be even more grossly over-represented.  This ploy would
not be illegal as the two parties are already registered with the
Electoral Commission and it has been proposed by one Labour MP who is
opposed to devolution and totally opposed to any form of PR.

> 	Anyway, I will talk about my own reasoning for thinking 
> that CPO-STV
> might be a serious improvement over Newland-Britain 
> (fractional transfer)
> STV.

I suspect it will make only a marginal difference in real elections, ie
occasionally it would have given the last seat to a different candidate.
[Howls of protest from those who specialise in counting angels on the
heads of pins!!  Yes, I know it will be possible to construct datasets
that show much larger differences.  But the real difference is between
any multiple single-seat system and first, Newland-Brittain STV-PR (the
largest difference), second, Meek STV-PR (a small improvement on N-B),
and then, CPO-STV-PR (a further small improvement).]

> 	What are the flaws of STV?

Like several other systems, it is non-monotonic.
Also, it can exclude a "Condorcet winner" when exclusions have to be

> 	My own meager experiments with CPO-STV shows that it 
> produces good
> Condorcet-efficient results in these little one-seat 
> subelectorates, in
> the midst of a larger election. So I am thinking that it 
> might really be
> the best system for really precise proportional 
> representation, the one
> which offers the most responsiveness, highest standards, etc. 

If you have a computer program for CPO-STV, why not let it loose on the
three datasets from the Dail 2002 election and see what differences it

> 	Does it succeed in this? Once again, it is hard for me 
> to test such a
> complex system, but I would be very interested if someone has 
> an idea of
> how to evaluate it.

I cannot comment on this directly (because I am not involved), but I am
aware there is great deal of work going on to compare the effects of the
Irish Rules, Newland-Britain and Meek versions of STV-PR.  There three
sets of rules are now all used for public elections in different
> 	To be honest, I'd be pretty pleased if this country 
> started going over to
> Newland-Britain or random STV within my lifetime.

"Random STV-PR" should NEVER be used.  There is no longer any acceptable
excuse for using it to avoid the calculations involved in the
Newland-Brittain system.  It is still used for Dail elections in
Ireland, but not for their Senate elections.  Newland-Brittain has been
used for all STV-PR elections in Northern Ireland since 1973.  There
should be no element of chance (order of ballot papers) in determining
the outcome of any election (other than that inevitable in the breaking
of complete ties between two candidates).

> 	Hmm. Well. Counting for CPO-STV can theoretically be 
> done by hand.
> Actually, the counting process would be the same as any other 
> rank ballot
> method.(That is, counting the raw data of number of voters for each
> expressed preference ranking.)
> 	As for calculating the results by hand, there is no 
> way, unless it is a
> very small election.

Neither Meek nor CPO-STV counts can be done by hand except for extremely
small elections.  Computer programs are available for Meek counts.
Tideman refers to programs for CPO-STV.

> 	I wouldn't much want to do a Newland-Britain STV 
> computation by hand
> either, though.

There are NO problems in doing Newland-Brittain STV-PR counts and
calculations by hand.  I do several every year.  When I attended public
elections in Northern Ireland ALL the calculations were done with
nothing more than a simple calculator.  Several computer programs and
spreadsheets are now available to assist with the side calculations.

> 	I think that with any ranked system, the election 
> commission should make
> the raw vote publicly known in addition to the results of the final
> computation. Whether it is IRV, Condorcet, or STV, it is 
> really important
> for people to have access to this information so they can analyse and
> understand it in different ways, rather than just having the 
> result fed to
> them and being otherwise in the dark.

This is not practical unless all the ballot information has been
captured electronically, either at the time of voting or in subsequent
scanning of ballot papers.

For the first time, electors in three constituencies in Ireland used
electronic vote recording for the 2002 Dail general election.  The full
ballot papers have been published on the websites I gave in an earlier
NB If you run them through an STV-PR program you are not likely to get
the same results as the official result, even if you use an Irish Rules
'random pick' counting procedure because the 'papers' were deliberately
shuffled before they were put into the published files.


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