That's Overhang! - The Snow In The Summer or So-So

4May

It's the Welsh and Scottish elections, and they use the top-up member system. In turn, that gives us the excuse to put on our Mitchell and Webb masks and seeing if we can shout,

That's Overhang!

We discussed the prospect of Overhang seats in October last year. Very roughly, we take the party list votes, and work out who would have won the seats if that were the only method of election. Then we compare this to the actual result; if there's a difference, the extra seat (the one with the smallest constituency majority) is an Overhang seat.

For instance, take North Wales. Here's the Party List table:

North Wales Party List, WA 2007
SeatLabPCConLD
151831505585026615275
22591525279251337637
31727716852167555091
41295712639125663818
51036610111100533055

It's a 13-member constituency, and the 13th highest vote is 12565, so the split of seats is Labour 4, Plaid Cymru 4, Conservative 4, Lib Dem 1.

Now let's add in the nine constituency results: Labour 5, Plaid Cymru 3, Conservative 1.

North Wales Party List + Constituency
SeatLabPCConLD
151831505585026615275
22591525279251337637
31727716852167555091
41295712639125663818
51036610111100533055

There are four top-up seats, awarded to the four highest residual votes in the regional list: a second and third Conservative member, the top Lib Dem, and a fourth Plaid. The final result, then:

North Wales Final Result
SeatLabPCConLD
151831505585026615275
22591525279251337637
31727716852167555091
41295712639125663818
51036610111100533055

But wait! Labour was only entitled to four seats in this region, yet they've won five.

That's Overhang!

How did this happen? It's the Vale of Clwyd result that spoils the pattern - Labour retained the seat by just 92 votes from the Conservatives, and if the Tories had won the constituency, the actual result would have tallied with the party list vote.

What can be done about this? It's possible for the Assembly to be extended to accomodate the extra Conservative; this approach is used in Germany and New Zealand, and is the standard method of dealing with Overhangmandates. It's possible for the result in the Overhangmandateseat to be overturned - in this instance, for the Vale of Clwyd to be represented by a Conservative member, even though they lost the election. This is profoundly undemocratic.

Instead, the Welsh Assembly (and the equivalent body in London, and the Scottish Parliament) ignores the Overhang. Those who voted Conservative in Vale of Clwyd have been doubly disenfranchised.

Similarly, in South Wales Central, Labour has 6 seats, this time at the expense of one LD. Pontypridd is the Overhangmandateseat here.

South Wales East is made a little more confusing by the presence of an Independent AM in Blaenau Gwent. Here, the standard process is to not count the constituency seat as existing in this election, and this produces matching results.

The greatest probem is in South Wales West, where Labour won all seven constituency seats. In order to avoid an Overhangmandate, Labour would need to win approximately two-thirds of the list vote. In the event, they got about 36%, causing two Overhang seats, one each against the Conservatives and Lib Dems. Edwina Hart (Gower, 4.3% ahead of C) and Andrew Davies (Swansea W, 6.6% ahead of LD) are the lucky AMs.

So, were the Welsh Assembly to use the German Überhang rules, the line-up would be:

Labour 26
Plaid  15
Cons   14
LibDem  8
Others  1

C, LD have 2 Overhang seats each.

In Scotland, there's a Labour Overhangmandate in Glasgow, at the expense of a fifth SNP list seat. Pauline McNeill in Kelvin has the smallest majority, 5.1% ahead of the nationalists, and smaller than the number of rejected ballot papers.

Similarly, in West of Scotland, Labour has one Overhangmandate seat, again at the expense of the Nationalists. Jackie Baillie in Dumbarton (5.4%) has the smallest majority over the SNP.

The final result, including the two Overhangmandateseats:

SNP    49
Labour 47
Cons   17
LibDem 16
Green   2
Others  1

Without the Overhang, the SNP has still won, 47-46. By fixing the rules in this way, Labour has given itself some major advantages in the post-election fallout. If it were Labour in the 47-46 lead, we would be justified in crying foul. As it is, the deeply unsexy topic needs further examination before the next election.

That's Overhang!

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