[EM] My summary of the recent discussion

[Juho Laatu]

On 4.6.2012, at 13.49, James Gilmour wrote:

>>>> I think Plurality can be claimed to be the ideal method for the 
>>>> single-member districts of a two-party system, but then one should 
>>>> maybe also think that third parties should not be allowed  to run, and 
>>>> we should stick to the same two parties forever.
>>> 
>>> I don't get it.
>>> 
>>> of course, if there are only two candidates, there is no problem with 
>>> Plurality (because it's also a Majority).
>>> 
>>> so how is Plurality so flawed if we accept that a two-party system is 
>>> fine and dandy?  if not Third parties, for Independents?
>>> 
>>> what is the scenario with two parties where FPTP is so flawed?
>> 
>> I think you already said it. If you want a system that allows 
>> also third parties and independents take part in the 
>> election, then Plurality is flawed. Only if you think that 
>> third parties and independents should nor run, and there 
>> should be only two parties, then Plurality is fine.
> 
> These contributions to this discussion take an extremely narrow view of representation of voters as it is clear this discussion is
> not about a single-winner election (state governor, city mayor) but about electing representative assemblies like state legislatures
> and city councils.  There can be major problems of representation if such representative assemblies are elected by FPTP from
> single-member districts even when there are only two parties.
> 
> Even when the electorates of the single-member districts are as near equal as possible and even when the turnouts are near equal,
> FPTP in single-member districts can deliver highly unrepresentative results if the support for the two parties is concentrated in
> particular districts -  as it is in most electorates.  Thus party A that wins 51 of the 100 seats in the assembly may win those
> seats by small margins (say 550 votes to 450 votes) but party B that looses the election with 49 of the 100 seats may have won its
> seats by overwhelming margins (say 700 votes to 300 votes).  Thus the 51 A to 49 B result is highly unrepresentative of those who
> actually voted: 42,750 for party A but 57,250 for party B.
> 
> These numbers are deliberately exaggerated to show the point, but here in the UK we see this effect in every UK General Election
> since 1945, where the "win small, loose big" effect of FPTP has consistently benefited the Labour Party at the expense of the
> Conservative Party.
> 
> And where such vote concentration exists  -  at is does everywhere  -  the result can be greatly influenced by where the boundaries
> of the single-member districts are drawn.  "Move the boundary, change the result".
> 
> These are fundamental defects of FPTP in single-member districts that must be addressed if you want your elected assemblies to be
> properly representative of those who vote.
> 
> Both of these defects has greater effect if the electorates are not so equal or if the turnouts vary with party support (as they
> certainly do in the UK).
> 
> So even when there are only two parties, FPTP is very far from "fine".
> 
> James Gilmour

Yes, that makes sense. FPTP in single-member districts is not fair in the sense that it gives only approximate results (due to the inaccuracy of counting the seats in single-member districts) and is vulnerable to gerrymandering.

A system that counts the proportions at national level (typically a multi-party system) would be more accurate. Also gerrymandering can be avoided this way.

The discussed proposal of changing the Plurality/FPTP method of the single-member districts to some other single-winner method has still many of the discussed problems (inaccuracy, gerrymandering). One could try to construct also two-party systems or single-member district based systems that would avoid those problems. But maybe proportional representation is a more likely "ideal end result". Practical reforms may however start with whatever achievable steps.

Juho