Fun-Size Elections

A fierce debate about the UK’s general election voting system is underway in the media. 

I wonder whether it's possible to produce a meaningful model using historic election results and assumptions about how people might select their 2nd and 3rd preferences, to add some analytical evidence to the debate.

I’m still working on the model.  If and when I finish it (I have to do this in the evening, you know) I’ll post my observations.

Before I look at some numbers that could affect an election result, here's a bit of fun from the 2010 election data...

1.        No one took the Kevin Phillips Bong prize by polling no votes at all (by the way, I saw this sketch live at the Drury Lane Theatre in London in the 1970s)

2.        Parties I’ve enjoyed spotting include:

a.        Animals Count, which is a new use for them which will be needed if AV is brought in

b.       The Bus-Pass Elvis Party, who clearly believe he’s alive and living in Kettering

c.        Get Snouts Out Of The Trough, possibly a porcine reference to the expenses scandal?

d.        I’ve always expected “None Of The Above” to appear on the ballot at some stage, but the closest I’ve seen is the No Candidate Deserves My Vote party, which ironically polled 327 in Stevenage

e.        Strangely, the Go Mad And Vote For Yourself Party struck a chord with 233 voters in Dorset South who didn’t realise they were voting for someone other than themselves

f.        The Reduce Tax on Beer Party is clearly the organisation most happy to declare its self-interest

g.       I can’t ignore the Monster Raving Loony Party, who continue to field multiple candidates, and as a result appear in my list of “large parties”

h.       Finally, there’s the wonderfully named Fancy Dress Party who probably have no policies at all but always look good

Anyway, down to the model.  Here’s some of the current output using data from the May 2010 election results.  It shows that in my home constituency of Birmingham Edgbaston, Labour got elected with just over 40% of the vote using the “First Past The Post” (FPTP) system.  Under the “Alternative Voting” (AV) system, the Christian Party’s 127 votes are split according to each voter’s 2^nd preferences.  All other voters’ ballots are amended to remove this Party if they’ve been selected.   This re-assignment of votes goes on until one party emerges with 50% or more of the votes.  You can see that even if all the “smaller” parties’ votes were transferred to Labour this way, they would still not reach 50%.  Eventually, in Birmingham Edgbaston, it’ll be Lib Dem voters’ preferences that’ll decide who wins.

You can also see that there are 650 constituencies (seats), contested by 138 parties.  But 80 of these parties only contest one seat, and 125 of them contest fewer than 10.   Here’s some basic analysis of parties which fought 10 or more seats, plus "smaller" parties who actually won.

Party	Seats fought	Seats won	Seats won 50%+ of vote	Votes cast	% of vote in seats fought	% vote Min	% vote Max
Conservative	631	306	126	10,703,654	36.95	4.40	62.80
Labour	631	258	76	8,606,517	29.71	2.25	71.96
Liberal Democrats	631	57	12	6,836,248	23.60	5.03	61.97
UK Independence Party	558	-	-	919,471	3.56	0.65	17.38
British National Party	338	-	-	564,321	3.70	0.40	14.60
Green Party	335	1	-	285,612	1.81	0.51	31.33
English Democrats	107	-	-	64,826	1.28	0.14	5.18
Christian Party	71	-	-	18,622	0.60	0.19	1.77
Scottish National Party***	59	6	-	491,386	19.93	7.66	45.68
Plaid Cymru**	40	3	-	165,394	11.28	2.10	44.33
Trade Unionist and Socialist	37	-	-	11,913	0.80	0.29	2.93
Monster Raving Loony Party	27	-	-	7,510	0.56	0.187	1.77
Socialist Labour Party	23	-	-	7,196	0.77	0.28	1.72
Alliance Party of NI*	18	1	-	42,762	6.35	0.59	37.23
SDLP*	18	3	-	110,970	16.47	1.06	48.58
Christian Peoples Alliance	17	-	-	6,276	0.76	0.11	2.83
National Front	17	-	-	10,784	1.45	0.28	4.87
Sinn Fein*	17	5	2	171,942	26.88	0.75	71.08
UCUNF UUP and CON*	17	-	-	102,361	16.32	3.11	30.44
Democratic Unionist Party*	16	8	-	168,216	28.34	7.58	49.81
Respect	11	-	-	33,251	6.84	0.39	25.12
Scottish Socialist Party***	10	-	-	3,157	0.81	0.51	1.41
Traditional Unionist Voice	10	-	-	23,300	7.26	3.54	16.78
Independents	235	1	-	175,604	1.63	0.10	63.26
Speaker	1	1	-	22,860	47.29	47.29	47.29

* Northern Ireland; **Wales; ***Scotland

These are my observations:

1.   Out of 650 seats, 214 were won with 50%+ of the vote, which means that 436 would have required transferring votes under AV

2.   Even the Speaker didn’t have a majority.  Traditionally, no-one is supposed to stand against the Speaker, but this time  it was contested by 10 other smaller parties/independent candidates.  If these others are objecting to the Speaker personally, perhaps because of his parliamentary expenses record, under AV it is entirely possible that he would not have won his seat

3.   The thinnest margin on the record is in Fermanagh & South Tyrone (Northern Ireland) where Sinn Fein beat an Independent candidate by just 4 votes, each polling 45.52% and 45.51% respectively.  This seat could easily flip but would not affect which of the main parties would rule in the UK– this is because the main parties do not field candidates in Northern Ireland and could not benefit from AV

4.   Northern Ireland, Scotland and to a lesser extent Wales constituencies have seats which have multiple candidates that each polled strongly, implying that these results would also be easily affected by AV

5.   There are also a number of constituencies in England where local issues have either unseated a mainstream party, or have split the vote; these also would be affected by AV.  Examples include:

a.   Birmingham Hall Green; Poplar & Limehouse; and Bethnal Green & Bow, where a Respect candidate probably took votes away from mainstream parties

b.   Barking; and Dagenham & Rainham, where a BNP candidate pushed the Lib Dems into 4^th place

c.   In Norwich South, the three main parties each polled between around 23% &  29%, but the Green Party took over 14%.  So only a small % of Green voters choosing differently could have flipped the seat

d.   In Wyre Forest, the 1-seat Independent Community and Health Concern party polled a stunning 31.7% of the vote, taking 2^nd place.  The same could be said of the 1-seat Independent Save Our Green Belt party who polled over 27% in Castle Point

I'm planning to do some more thinking and then adapt the model to enable an AV system.  

What assumptions should I make?