A friend commented on facebook (and rightly so) that the list of MEP candidates in London was very distorted in favour of getting us out of Europe. I pointed out that the MEP electoral system we used was vulnerable to vote splitting (it has to be: You only get to vote for one party), so in some sense this was a good thing (although I hate to celebrate bad voting systems).
But it made me realise that I’m actually incredibly unclear as to what the voting system for our MEPs is. It turns out that I’m not alone. The available literature is terrible. It’s scattered, hard to find and poorly explained. This is my attempt to make sense of it. You might want to just go read the wikipedia page instead, as it’s actually pretty good, but I was most of the way through finishing this when I found that particular page and decided I might as well keep doing the research. These are my research notes.
Note that this is UK specific, though the details are not unique to us in that a lot of other EU countries use similar systems. The EU imposes various restrictions on the voting systems used. It requires that the system be a form of proportional representation, and provides some bounds on what sort of proportional representation, but it does not mandate a specific form. It also allows for countries to be divided up into constituencies who each use a form of proportional representation (it is unclear to me what would happen if a country wanted to subdivide into constituencies of one member each and use FPTP in each of them. This would obviously be extremely non-proportional). Most countries don’t, but some do.
So step one is that there are 12 constituencies in the UK. Each of these elect multiple MEPs, with a different number for each constituency. Note that these constituencies do not map directly onto the constituencies for electing your MP – they are much larger. I’m unclear on whether some of the normal electoral constituencies cross multiple MEP constituencies but I don’t think they do (EDIT: Alex Foster confirms in the comments that they don’t).
The regions and number of MEPs are as follows:
- Eastern – 7
- East Midlands – 5
- London – 8
- North East – 3
- North West – 8
- South East – 10
- South West – 6
- West Midlands – 7 (NOTE: This is one more than last time, apparently due to the Lisbon Treaty. The last election was rerun with the original counts to make up the difference when this change came into effect)
- Yorkshire and Humber – 6
- Wales – 4
- Scotland – 6
- Northern Ireland – 3
So there are 73 UK MEPs in total (up from 72).
How these MPs are then elected varies by constituency. Every constituency other than Northern Ireland uses the D’Hondt method. Northern Ireland uses STV.
…or at least that’s what seems to be said all over the place, e.g. in the gov.uk page about voting systems, but the guidance for returning officers paper makes no mention of anything other than D’Hondt. Additionally that’s the only place where I’ve found them to come out and say “We use the D’Hondt method” as opposed to a half-baked and incomplete explanation of it. I’m pretty sure it’s accurate though.
The D’Hondt method is essentially a (supposedly proportional. I haven’t seen the maths that justifies this, but it seems to work out that way in examples) extension of first past the post to multiple members.
It’s a party-list proportional method. What that means is that you vote for parties, not individuals, and each party puts forth a list of candidates. If they get N seats then the top N people on their list get in.
The way it works is that you run as many rounds as you are electing candidates. In each round, a party gets the score equal to the number of votes it got divided by 1 + the number of candidates it has already had elected (so if it has no candidates so far its score is the number of votes it got. If it has one candidate elected already its score is half that, etc). The party with the highest score gets a candidate and you move onto the next round until you’ve elected enough members.
(It appears to be the case that all MEP elections must use either a proportional party list system or an STV system. I am unclear on exactly what “the list system” constitutes here, but it doesn’t appear to be as restrictive as to specify the D’Hondt method given the range of examples described).
Northern Ireland elects its MEPs with the variant of STV it normally uses. It’s a pretty damn good one. The neat feature of it is that it avoids any ambiguity over which votes are transferred (which can affect the result of an election quite significantly) by transferring all votes but at a fractional value. You calculate the number of excess votes for a candidate that should be transferred onwards and distribute that to each vote according to the fraction of the vote it made up (this isn’t the same as distributing it equally amongst each voter being transferred onwards because some of those may already be at reduced value because they were transferred from a previous candidate). This is the Gregory method of STV.
Anyway, this is most of the information I was interested in finding out. If you want to find out a bit more, go read the Wikipedia page I linked.