Iain Dale has popped his head above the parapet today and highlighted some of what he perceives as the problems with the Single Transferable Vote system. He also briefly touches upon AV and AV+.
I tried to leave a comment on his post but it got so long that the system rejected it! Instead I thought I'd interweave my thoughts on here with his. Iain's post is in italics and my responses are in bold:
Several commenters in the previous post have taken issue with my assertion that Proportional Representation, and most especially the STV system, weakens the constituency link - and this is the reason why I cannot support it. Let me explain.
The proponents of STV deny that STV weakens the constituency link. In their view, if you have bigger constituencies with 10 or 12 MPs you still get the constituency link because seats are awarded proportionate to the votes received. Well, in the sense that you have constituencies and MPs who represent them, the constituency link still remains. Sort of.
The trouble is, that in 3, 6, 8, 10 or 12 member constituencies no one would really know who their MP is, just in the same way that no one now knows who their MEP is. The second effect is that when they eventually find out who their MPs are, which of them do they contact with a constituency issue? The probability is that they will contact the MP representing the party which they voted for. Nothing wrong with that, you may say, but I think it is a good thing that current MPs represent ALL their constituents, not just those who put a cross against them on the ballot paper.
This point about STV "weakening" the constituency link is one that can be debated. It depends what you consider a good link between MPs and constituents. Having one MP per constituency is of course one way to do it but there are disadvantages to this way too, for example someone who is say viscerally opposed to Labour may have to deal with a Labour MP. It is also possible that you want your MP to represent your views about something to which they themselves are diametrically politically opposed to. Now in both of those cases it is possible under a single member system for the constituent to be represented in a way that satisfies them but I would argue that under a multi-member system they would have a better chance of being well represented. Not least because if one of their MPs did not do a good job they could try one of the others. Conservatives relish competition in most other areas. It seems slightly odd how opposed they are to that same competition when it comes to the political sphere.
One other minor point, most advocates of STV do not suggest seat sizes of more than 6 MPs. Between 4 and 6 is the optimal amount. I just raise this because you lead with an example of between 10 and 12 which is basically double what would be likely to happen and is therefore potentially a bit misleading.
Can we also dispel the myth that AV is in any way proportional. The Jenkins proposal of AV+ where you had additional members would be. But it would put a lot more power in the hands of the central party.
AV is indeed not proportional. I have heard a number of Tories using this as an argument against a "Yes" vote. However as you well know the Tories refused a vote on a proportional system. AV is a compromise which ensures a fairer result in each individual constituency and avoids the situation at the moment where nearly 2/3rds of all MPs (in the 2010 election) got in with less than 50% of the vote in their seat.
AV+ is a bit more proportional as you state but that was also not on the table from the Tories.
And of course under STV, the party has even more power and influence over candidate selection.
This final point is just plain wrong. There is no reason why under STV the central parties should have more control over who is selected. That is entirely down to the way the selections are made. They could be similar to now with local parties choosing their candidate(s). It could be instead through open primaries or other mechanisms that allow local people greater control over the candidates. Also, because each party is likely to be fielding multiple candidates to maximise their vote across the constituency there is a built in incentive to field a diverse range of candidates which should lead to more women and ethnic minority candidates standing.
No electoral system is perfect but most proponents of STV think that it is the least worst system available and that FPTP is just about the worst worst! AV is an improvement on the status quo. FPTP has all sorts of problems which I expect will be highlighted during the coming campaign.
UPDATE: It looks like my comment on Iain's post did get through after all (twice!) despite the error messages I received.