2005 Elections

• A surge to the centre
• How did your constituency move?
• Why three way?

The BBC sums up the vote in the 2005 General Election as a "3.0 percent swing from LAB to CON" (http://news.bbc.co.uk/1/hi/uk_politics/vote_2005/constituencies/default.stm) .

But if we look at how the share of the vote between the three big parties has changed in each constituency from 2001 to 2005, we see a different picture.

Each cross represents a constituency in England, Scotland or Wales. A cross's position shows how the share of the vote won by the three big parties was split between them in that constituency. A cross in the red zone usually means a Labour win, but in a few cases the seat was won by a fourth party (e.g. the SNP) while Labour got more votes than Conservative and Liberal Democrat. Similarly for crosses in the orange and blue zones. You can interpret the movement of seats as two-way swing by referring to this diagram: Outside the triangle of black lines there is no argument about which of the three big parties voters preferred. Inside are seats where the winner got less than 50 per cent of the 3-way vote. With a different voting system like approval or alternative voting, these seats could have been won by a different party.

Are you seeing what I'm seeing? Upward not sideways?

• The dominant swing is from Labour to Lib Dem, even in Tory seats.
• But there are many exceptions, with vote shares moving in all directions in the Conservative and Lib Dem zones.
• On the boundaries (marginals)...
  • Some Conservative wins from Labour are because of Lab to Con swing but more rely on Lab to LD swing.
  • There is little movement in the Labour vote near the Con / Lib Dem boundary.
  • So anti-Tory tactical voting may have helped in some Labour seats but not others, and seems to have done nothing for the Lib Dems. Anti-war tactical voting may have contributed to the outcome, but its effects are buried in the overall Lab to LD movement.
• Most of the handful of seats moving right to left are Scottish constituencies where the comparison between 2001 and 2005 is imprecise because of boundary changes. There is very little swing towards Labour anywhere.
• The major shift is towards the centre of a three-party map. If you believe in voting reform, the votes inside the black triangle are those you don't trust to represent people's real preferences. Their number is increasing.

The clustering of votes in the centre is even clearer if we compare Labour, Conservative and Other (which includes the Lib Dems, Nationalists and Independents). Here is the current picture, with a significant majority of seats inside the black triangle.

You can change the two maps here to apply to your constituency by clicking on the appropriate link below.

Your constituency in 2001	Your constituency in 2005

Most ways of summing up elections are two-way: "Swing", "X majority over Y". But most elections are multi-way and the overall picture is more complicated than just the average of lots of little pictures. A multi-way visualization is valuable, not only because many people support third, fourth and fifth parties, but also because it shows the electorate is not a homogeneous lump who "wanted a Labour government with a reduced majority, and that's what the election gave them", which seems to be the pundits' favourite analysis.

A three-way visualization doesn't tell the full multi-party story, but it's a step in the right direction. The pictures above (for 2001) were the first I'd seen. After a Google search turned up only the 3D swingometer on Wikipedia, I tried to do better and came up with the triangular map. But someone at the BBC had beaten me to it: Peter Snow had one on Election 2005 -- and a much more beautiful one than mine. Peter's didn't really show the reality of a 3-party contest though -- he kept calling it a battleground and fixated on the fronts, where the battles were all two-way, as usual. People turned a different colour when they "fell in battle" instead of moving. It's no surprise that the BBC also didn't have the black inner triangle. Pointing out how many contests have questionable outcomes doesn't have the drama of winner-takes-all conflicts. But it would allow Peter to do some interesting what-ifs if we had an alternative vote system:

	Peter: What if all those non-Labour voters in Labour seats were prepared to use their second preference votes to get Labour out at any cost?
	Peter: But what if they were saying, let's give Labour a kicking but not let the Tories in?

The first example assumes that Labour voters don't want either Con or LD in non-Labour seats (reflecting the Labour/non-Labour antagonism of Peter's hypothetical question), whereas the second example assumes Labour voters share the "don't let the Tories in" philosophy so prefer LD in non-Labour seats. Those arguments may be a little too nuanced for Election night TV, but they're plausible, and they show how people's preferences really can affect outcomes under the alternative vote.

Some more reasons to adopt the alternative vote rather than first-past-the-post are given here.