It Ain’t Fair!

I know you don’t want to hear my views on the General Election campaign, which is just as well because I am finding it so vapid and uninspiring that I don’t have much to say. Instead I want to talk about this little toy that the BBC have come up with:

Its quite a nice thing to play with but I don’t know how accurate it is, particularly when stretched beyond plausible results. It makes no attempt to define who the “other” parties are, so it can’t model things like UKIP stealing off the Tories or anything clever like that. Even so, I quickly tired of playing out plausible election scenarios and started using it to find illustrations of how monstrously unfair the UK electoral system is. Prepare to laugh and/or cry as we ask some questions:

Q1. Who wins if each party gets the same vote?

That’s easy. Reserve 10% for the “others” and then give the main parties 30% each:

Party Vote Seats
Conservative 30.0% 206
Labour 30.0% 315
Lib Dem 30.0% 100
Other 10.0% 29

That is appalling! Labour gets very close to a majority despite having won no more votes than anybody else. The Tory claims that the system is fixed against them seem well founded but the Lib Dems have the most to complain about.

Q2. How many seats does it take each party to win a majority?

Obviously this depends on what the other parties get. Lets fix the “others” at 10% and then try to find the lowest vote that delivers each party a majority. A majority is 326 seats, by the way.


Party Vote Seats
Conservative 36.9% 326
Labour 22.6% 182
Lib Dem 30.6% 113
Other 10.0% 29

A couple of interesting points here:

  • The Tories would benefit from Labour being hammered by the Lib Dems. It lowers the bar for them slightly. As this is unlikely to happen the bar is actually higher than 36.9%.
  • The other point is how far ahead of Labour the Lib Dems are and still they get less seats. What does it take to elect a Lib Dem around here?


Party Vote Seats
Conservative 24.7% 136
Labour 30.4% 328
Lib Dem 34.9% 157
Other 10.0% 29

Two interesting points comparing this with the Tories:

  • The bar for Labour is far lower than for the Tories. Astonishingly so.
  • As for the Tories, the best scenario for Labour is one where the Lib Dems do well and hammer their other opponent. It seems the Lib Dems are better at depriving other parties of MPs than they are of winning them for themselves. Notice that the Lib Dems actually came first in this scenario, for what little good it did them. In a more plausible Tory / Lib Dem situation the bar for Labour is raised but remains far lower than for the Tories.

Liberal Democrats:

Party Vote Seats
Conservative 26.4% 128
Labour 23.4% 166
Lib Dem 40.2% 327
Other 10.0% 29

This makes you wonder why Lib Dems get up in the morning! They need to pretty much wipe out both the other parties to get anywhere.

Q3. What vote would it take to deliver each party the same number of seats?

This is a matter of fiddling with the sliders until the results come out more or less even.

Party Vote Seats
Conservative 29.6% 206
Labour 23.7% 207
Lib Dem 36.8% 208
Other 10.0% 29

By now, this isn’t telling us anything we don’t already know. The system makes it far easier for Labour to get seats and far harder for the Lib Dems.

Q4. Can Labour get a majority even if the Tories get more votes than them?

For this we put the Lib Dems on a plausible 20% and give the Tores a slight lead over Labour.

Party Vote Seats
Conservative 35.3% 242
Labour 34.6% 327
Lib Dem 20.0% 52
Other 10.0% 29

So the answer is yes. Furthermore, it is not that an implausible result. A swing back to Labour over the next few weeks might actually deliver this travesty of a result. Now I hate the Tories as much as any sane person but I love democracy more and that would be a disastrous result for British democracy.

Q5. Could Labour come third and still win?

For this one we set the votes at 31%, 30% 29% and see what happens:

Party Vote Seats
Conservative 31.0% 222
Labour 29.0% 297
Lib Dem 30.0% 102
Other 10.0% 29

So the answer is no, although they can still be the largest party.

Q5. What affects the Lib Dems more, their own vote or the swing between Labour and Tory?

For this we take the April 9th YouGov poll as a starting point. From that we swing the Lib Dems up 4% (from a starting point of 18%) and see what happens depending on who they take the votes off.

Party Vote Seats
Conservative -4% -51
Labour +31
Lib Dem +4% +19
Other +1

So the Lib Dems clobbering the Tories helps Labour more than the Lib Dems.

Party Vote Seats
Conservative +21
Labour -4% -38
Lib Dem +4% +16

So the Lib Dems clobbering Labour helps the Tories more than the Lib Dems.

Party Vote Seats
Conservative -2% -14
Labour -2% -6
Lib Dem 4% +19

So the Lib Dems hitting both equally yields only small benefits but at least it avoids helping the others. It vindicates their strategy of targeting both of the main parties equally.

What does this all mean?

It tells us that either the BBC model is hogwash or the electoral system is unfair. The former may be the case but everybody knows the latter is true anyway.

It gives the Tories an incentive for electoral reform, which I doubt they will take. They will go for a Boundary Commission instead and try to fix the bias against themselves without giving the Lib Dems, Greens or UKIP  a fair chance.

What it doesn’t do is tell you how to vote. For what it is worth, here is how I think you should vote:

  1. Ignore the national picture entirely. Each constituency is a separate election.
  2. Work out which candidates can’t win in your constituency and disregard them, even if you would like to support them.
  3. Out of the ones with a realistic chance of winning, pick the one you think would be the best MP (or the least bad, anyway).
  4. Vote for that candidate and don’t feel guilty about it.
  5. Start demanding electoral reform so that the next election after this can be fair.

If you are unlucky, you find that this fails at step 2 because there is no hope in hell of unseating the incumbent in your constituency. If that is the case, I won’t blame you for omitting step 4 and proceeding directly to step 5.


April 10, 2010. Links, Media, Politics, Sensible.


  1. danielrigal replied:

    As the polls unexpectedly come to resemble my Q1 scenario, and Q4 comes into ever sharper focus, apparently David Cameron has been telling people that we have an electoral system “that really works”. Needless to say, the ever wonderful Marina Hyde is taking the, well deserved, piss out of him for it.

  2. danielrigal replied:

    I just saw Cameron on TV, clearly rattled, slagging off PR but calling for boundary reform. How psychic am I?

    It also highlights an interesting difference between the Tories and Lib Dems. The Tories only want reforms that benefit them while the Lib Dems have long held out for a system that is fair to all parties and have consistently opposed offers of a three party stitch-up system that would have benefited them but still frozen the Greens and UKIP out.

  3. danielrigal replied:

    Very interesting analysis of the same sorts of things without assuming uniform swing here:

  4. danielrigal replied:

    Well, it seems we have the optimal result for heaping humiliation on everybody concerned. Labour lost. Tories failed to win. Lib Dems failed to break through. Pollsters left looking like fools again.

    Meanwhile David Cameron has apparently offered the Lib Dems a switch to AV. AV is the electoral system most likely to shaft the Tories (which is why Labour like it). It is not close to proportional, so the Lib Dems don’t like it, and God only knows why the Tories have alighted on it.

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