The perils of projecting the impact of boundary changes from previous election results

There’s been an understandable flurry of interest in The Guardian’s reported projections of what boundary changes might mean for the parties, but there are two major caveats about the nature of such projections.

From what I’ve seen, Lewis Baston (as I would expect) has done the numbers well, but not only do we not yet have the actual boundaries on which to make projections but also projections based on looking at previous election results have a decidedly ropey record when it comes to Liberal Democrats MPs.

That is because the party’s voting support is far less polarised demographically than that of Labour or the Tories, so knowing the sort of area being added to or removed from a constituency acts as a far less helpful guide to what that might mean for Liberal Democrat support at the next election than it does for either of them. It’s also because of the related ability of MPs in particular (and other candidates to a lesser degree) to therefore build up support in areas that previously looked very weak for the party.

There is nothing new in this phenomena, but the 2010 general election provided one very striking example in Brent Central. Many outsiders were in advance confidentially predicting that Sarah would be defeated because of the apparent large Labour majority in that new seat, based on calculations using previous local and general election results.

However, one of the main reasons for Sarah choosing to fight that seat was the polling the party did (and which I did the analysis for) during the last Parliament. At the time when to the outside world those calculations were showing a large Labour majority, the actual polling was showing something very different – a seat where the Liberal Democrats were the narrow favourites to win. Alas, the other part of my polling analysis also turned out right – that the odds of winning Hampstead & Kilburn were slightly less good.

This sort of experience has been repeated many times in the past, with Liberal Democrat MPs seeing off apparently massive odds because the nominal calculations didn’t actual reflect the realities on the ground. (Long-standing Scottish members may well remember the case of Malcolm Bruce’s boundaries in the 1990s in particular…)

Fewer seats means bigger seats, which means most Liberal Democrat MPs will have to fight new territory. That, however, is nothing new and in previous boundary changes it has not caused significant problems for the party. It’s not the boundaries that will decide the fate of the bulk of the Parliamentary Party; it’s the party’s performance in government.



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  • The boundary changes are a farce, and not because any party will do better or worse, but because the commission has its hands too tightly tied. Whilst I agree they are currently in dire need of adjustment the Tories got what they wanted and the commission is now more or less redundant. Luckily I live far enough into Devon to avoid the Devonwall fiasco. It will be an issue in this part of the world though and one that will cost yet more votes.

    The reality is that the political scene will be so different in 2015 that no one will ever really know whether it costs Lib Dem seats. Expect some smirks from Labour benches if it does appear to though.

  • You have to wonder about the ability of the Lib Dem strategic thinkers. Boundary reforms in exchange for a AV referendum. Did Lib Dem internal polling indicate that the AV referendum was easy to win at the time this exchange was negotiated?
    It’s difficult to see why the possibility of voting reform, even if it was a miserable little compromise, was exchanged for the certainty of boundary reforms. The Tories knew that no matter what they’d get their boundary changes. What, assuming the worst would happen, did the Lib Dems think they’d gain from this deal? What was the perceived advantage over the status quo in losing the AV referendum?

  • Yes this all looks silly with boundaries moving every 5 years. Local government has to government has to go through this kind of thing from time to time and the world hasn’t collapsed.

    One way to keep changes down to a minimum would be to have more than one MP per seat, as a larger seat would be be able to maintain its shape with population changes and keep within the % variance limits.

  • Matthew Huntbach 7th Jun '11 - 8:49am

    Yes, the projections on the boundary changes show as ever that the commentariat haven’t a clue about how the Liberal Democrats work. If you take a Liberal Democrat held seat and add extrapolated results from a few neighbouring wards to make it bigger in order to model the boundary changes, of course you’re going to see a big drop in the share of the vote. Quite likely little campaigning activity will have taken place in those neighbouring wards because activists there will have been directed to the target constituency. How many of us routinely cross constituency and borough boundaries at general election time to put our efforts into what are the most winnable seats? Add another couple of wards to the seat, and quits obviously you’ll see a marked increase in Liberal Democrat activity in those wards, so the figures next time round will not reflect what they were last time round.

    The commentariat cannot see this because the commentariat thinks politics is all about them and the people they talk to in the Westminster bubble, with votes in the country swinging entirely on what the Westminster bubble portrays to the people.

  • @Matthew Huntbach

    The commentariat cannot see this because the commentariat thinks politics is all about them and the people they talk to in the Westminster bubble, with votes in the country swinging entirely on what the Westminster bubble portrays to the people.

    How’s the Lib Dem vote holding up?

  • Liberal Neil 7th Jun '11 - 9:38am

    @Lloyd There has to be a review every five years, that doesn’t mean there will be boundary changes to every seat every five years. When changes do take place, in most areas, they will be relatively small changes. Every so often there will be bigger changes, for example hwne there have been local government ward boundary changes in the area, but probably not that much mor frequently than has happened in the past.

  • Given that Lib Dem candidates and MPs stood on a manifesto which committed to reducing the number of MPs the boundary change would always result on that (even if we would rather they went hand in hand with more meaningful electoral reform).

  • Yes well Brent looksn like an exception – look at Meon Valley or Filton and Bradley Stoke. Or new boundaries at Winchester and Romsey, or in Cornwall or Rochdale.

    On the otherhand, even a week out from polling day the guardian was predicting a Lib Dem gains in places like
    Hampstead and Kilburn and the list of near misses in 2010 exceeded the near misses in any other election I can think of see:

    what is more worrying is that Sarah Teather is now spending a lot of her time as a junior minister which is hardly likely to win votes in 2015.

  • David Allen 7th Jun '11 - 5:51pm

    “Add another couple of wards to the seat, and quits obviously you’ll see a marked increase in Liberal Democrat activity in those wards, so the figures next time round will not reflect what they were last time round. The commentariat cannot see this…”

    What about when a seat splits down the middle, and the activists have to take on tens of new wards?

    I hereby claim the mantle of Mystic Meg. On boundaries:

    on fees:

    and on Clegg!

  • Matthew Huntbach 8th Jun '11 - 9:30am

    David Allen

    What about when a seat splits down the middle, and the activists have to take on tens of new wards?

    Sure, then it becomes more difficult, but my point remains. Media predictions are almost always based on looking at past figures and applying a uniform national swing. The national media tends to think local activity counts for little in election results, so they really do think this is accurate. The Liberal Democrat vote is particularly dependent on local activity, which is why predictions for the results in terms of seats based purely on national swing often don’t work. For us, the pattern of activity will be fitted into whatever boundaries we have to work with. It’s easiest if a couple of wards that never got worked get added onto a target constituency – suddenly they get worked hard. Harder, obviously if a target constituency gets split in half, each half taking on large amount of unworked territory.

    On “g”‘s question, that’s a separate issue. The predictions quoted are about measuring the effect of boundary
    changes, not about an overall decline in the LibDem vote due to dissatisfaction with the party’s role in the coalition.

  • I apologise if my comments come across as somewhat simple but I don’t agree in some part to these boundary changes. I should point out that I live in a town of around 30,000 people in East Anglia who are quite likely to be relocated (on a map at least) to the neighbouring county based purely on the number of voters rather than the actual number of people living there. And of course the people who can vote can’t do anything about these boundary changes because it’s out of our hands. I don’t remember voting for boundary changes last general election, do you?

    Under a democracy surely reducing the number of voices in a parliament is not a good thing but this is what is being put forward. I understand why the new boundary ideas are in fact being pushed forward but the social and economics of these changes are not being properly thought through. I wonder how much is all of this going to cost across the UK in the short and medium term and perhaps with this in mind we should shelve this idea and press on with the real task in hand in getting the UK back on the road to recovery.

    Ultimately this is a waiting game until September but it looks as if the dye has already been cast and there’s nothing you or I can do about it.

  • Just before the grammar and boundary police get me…I should have said ….’it looks as if the die has already been cast…’

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