The electoral system used for elections to the Scottish Parliament, the so-called additional member system, is often misunderstood by many voters.
All the other electoral systems used here (FPTP for Westminster, STV for the councils, and d’Hondt for Europe) have the property that each voter gets only one ballot paper, but AMS gives you two, which leads to confusion about their relative importance.
The answer depends on where in Scotland you live. In Glasgow and the West of Scotland, Labour are dominating and thereby winning the majority of constituencies.
As an example of this situation, let’s look at the Eastwood constituency within the West of Scotland region at the last elections back in 2007. The result was that Labour’s Ken Macintosh won Eastwood, and that Labour got 0 list seats (but 8 out of 9 possible constituency seats), SNP 4 list seats (in addition to 1 constituency), the Tories 2 list seats and the LibDems 1 list seat, for a total result of Lab 8, SNP 5, Cons 2 and LD 1. The list MSPs included two candidates from Eastwood (the SNP’s Stewart Maxwell and the Tories’ Jackson Carlaw), so this constituencies in effect saw three of its candidates elected.
Now let’s look at some different scenarios:
It’s therefore clear that the only important question was whether Labour won Eastwood or not, and that it would have made sense for SNP and LibDem supporters to have voted Conservative if they wanted to hurt Labour.
So what about the effect of the list vote? Let’s again look at some scenarios, assuming that Ken Macintosh had won the constituency. Remember that the baseline scenario is Lab 8, SNP 5, Cons 2 and LD 1.
What we are seeing here is the effect of the SNP having won the 7th and last list seat, and the Tories being due the next list seat, so when somebody wins a seat, it comes from the SNP, and if they lose one, it goes to the Tories.
However, the overall picture is clear: A vote on Labour is completely wasted when it comes to the list votes, whereas it makes a difference for all the other parties.
The conclusion is therefore clear. If you were a voter in Eastwood back in 2007, in retrospect these were your choices: For the constituency vote the choice was between Labour and the Conservatives, and for the list vote the only relevant choices were Conservative, SNP, LibDem or perhaps Green.
Given the notional results for 2011, it’s very likely that Labour will win so many constituencies that a list vote for them will again be completely wasted. This again means that the only real decision for the constituency vote is whether to vote for or against Labour. The voting recommendation for 2011 is therefore the same as for 2007.
On the other hand, in most Scottish electoral regions, one party does not win the vast majority of constituency seats, and the effect of this is that the constituency vote never matters. As an example, let’s look briefly at the results from the North East Scotland region.
The results in 2007 were SNP 6 constituency seats + 2 list seats = 8 seats in total, Labour 1 + 2 = 3, LD 2 + 1 = 3, and Cons 0 + 2 = 2. Here are the different alternative scenarios:
This is actually what the AMS system is supposed to do: The constituency vote is supposed to allow people to decide who they want to represent them (as opposed to which party), whereas the list vote is supposed the allow people to decide which party the want to represent them (as opposed to which person).
It’s just that it doesn’t quite work like that when one party is winning too many constituencies within a region, which is why the constituency vote in Eastwood is important for deciding how many MSPs Labour will get in total, rather than just on deciding on the personal merits of Ken Macintosh.