How uncommon?

Today–one day before UK election day–the UK Polling Report average of polls shows the Tories on 35%, Labour on 28%, and Liberal Democrats on 27%. Needless to say, this would not be an outcome that matches Duverger’s Law, were it to materialize in the actual voting. But just how uncommon would such a result be?

In the database I assembled for my chapter in the edited volume by Andre Blais, To Keep or Change First Past the Post, I have 210 elections under FPTP. These include three or four decades worth of elections from the UK, Canada, New Zealand (before it changed from FPTP), India, Botswana, all but the smallest Caribbean island states, Belize, and all Canadian provinces.

In these 210 elections, how many saw the largest party have less than 36% and the third party have more than 25%?

One. Nova Scotia, 1998. (In the comments, Joffré reminds me that there has been one more since the period for which I collected data: Quebec in 2007. And it’s the best example of all, with the three parties ranging from 33.1% to 28.3% of the vote!)

If we expand the band a bit further, to something that might be more reflective of the final result (just a hunch, not a prediction), to less than 38% for the first party and still over 25% for the third, we pick up just two more: Nova Scotia 2003* and Ontario 1975.

In all of these three, the top two parties were within two percentage points of one another, whereas in the UK election it is likely that the second and third parties will be closer than the top two. Each of these three produced a no-majority situation (a hung or balanced parliament): The top two parties tied in seats in Nova Scotia 1998, while in 2003 the leading party (Conservative) won 48% of the seats on 36% of votes (whereas the Liberals managed 23% on 31%). In Ontario 1975 the Conservatives and Liberals were 41%-29% on seats despite being 36%-34% on votes.

In none of these did the third largest party by votes gain more than 30.4%, or less than 26.9% of seats. This election almost surely will see the third party do considerably better or worse than that. If the third party in votes is Labour–still a distinct possibility–it will almost certainly obtain over a third of the seats.** If it is the LibDems, the third party is likely to have not much more than 15% of seats. (Earlier projections that had Labour third in votes but first in seats no longer look likely, but such a result certainly remains imaginable.)

Looks like a lot of us over here will be staying up rather late on Thursday.

______
* There was an intervening election in 1999 that does not make the cut.

** In addition to UK Polling Report, see Politics Home. On the other hand, FiveThirtyEight is projecting Labour on 198 seats, which would match the 30.4% won by the third-place NDP in Ontario in 1975. (The FiveThirtyEight projections for the LibDems are on the high side–currently 113.)

Travel note: This was composed and uploaded somewhere south of Preston, on a train between Glasgow and London. Nice countryside (despite that junkyard we just passed), and farther north we saw lots of itty bitty lambs.

12 thoughts on “How uncommon?

  1. The British election seems to have developed into two distinct contests-there’s one where the Conservatives are waiting to be crowned, regardless of how far away they are from a majority, as long as they are credibly ahea din the popular vote, and the contest for second place in the popular vote between Labour and the Lib Dems-that seems to have moved in the direction of the former, but who knows what will happen.

  2. I think in single member plurality systems, many voters instictively construct a virtual single member majority system, in that they look at where the parties are in the polls before the election, and supporters of the third place parties shift their votes to one of the two leading parties, to avoid their votes being “wasted”.

    This certainly happened with Nader voters in the US in 2000, the election itself saw a significant drop in Nader’s support, and a much higher level of support for Gore, than a week earlier. For this reason I am sceptical of analysis which simply assigns Gore all of Nader’s actual votes for scenarios where there is no Green candidate, there is evidence that the Nader supporters who were inclined to vote for Gore in fact wound up voting for Gore, and the core support that the Greens were left with were more resistant to the Democrats.

    Also, it would explain why its rare to see three strong parties in multiparty systems, its usually two strong parties and one or several smaller parties. Though if the UK had proportional representation, I don’t think there would be one big “third” party like the Liberal Democrats, but several smaller ones.

    Of course, this can backfire with ignorant voters, for example all those left-leaning Canadian voters who voted Liberal instead of the NDP in marginal Conservative-NDP seats, so as to not waste their votes!

    Still, I’m less impressed with single member majority than I was before because I’m not sure its necessary. With media coverage emphasizing the horse race aspect, generally anyone voting for a candidate on election days that the polls have shown coming in a distant third, really doesn’t want to choose between the top two. If there is a runoff, they would probably skip it. I’m not sure what the value is of them forcing a choice.

    Also, I suspect in the UK you will see many people shift from the Liberal Democrats to the Conservatives to make sure that there is no chance of Labour getting back into power, certainly the Tory leaning newspapers have been campaigning for this in the last few days and its bound to have an effect.

  3. Good call, Joffre: while I wrote about that election (several plantings) here at the time, the data for that book chapter went through 2005 or 2006 only.

    And I might note that Quebec still has FPTP…

  4. > ‘… supporters of the third place parties shift their votes to one of the two leading parties, to avoid their votes being “wasted”….’

    Which means, by the way, that claims that FPTP ‘at least’ elects ‘the candidate with the most positive support’ are unreliable. A plurality of votes may well include ballots from voters who preferred a “hopeless” candidate and voted tactically. And some major-party candidates may be better than others at persuading third-party supporters not to “waste their vote”. How often? No one knows.

    In fact, FPTP is often defended by its supporters on precisely this basis – it makes minor-party supporters wise up and get realistic – perhaps unaware that it directly contradicts their other ground for supporting FPTP, that it elects the “most popular” candidate rather than the “least unpopular”.

    In other words: It’s trite to say that FPTP often elects candidates who lack (absolute) majority support, but it’s not often realised that it may very well elect candidates who don’t even enjoy (simple) plurality support – the very thing it’s advertised for.

  5. While waiting up for the UK results, the 117 riveting pages of the Research Report “Choosing an Electoral System” should do the trick.

    Two things especially recommend it: the claim that it is “something between a tourist guide and a cook
    book,” and the Who’s Who of 14 experts acknowleged for comments, among whom are one Matthew Shugart.

    The Lib Dems manifesto calls for STV (are they still thinking of four- and five-seaters? they don’t say.) But look what they said last spring:

    “There is growing consensus that a new electoral system is needed in the UK. The Liberal Democrats believe the best system would be multi-member constituencies elected by Single Transferable Vote, but it is unlikely that agreement could be reached on such a system in the timescale necessary. Roy Jenkins’ review of electoral systems in 1997 recommended the Alternative Vote + system; Labour committed in their 1997 manifesto to a referendum on this; and there are an increasing number of people, including cabinet members, supporting the move now.” (AV+ is an MMP, or “top-up,” model.)

    “We therefore recommend that the Jenkins AV+ recommendation be put to the country immediately at the end of this 100 Day Reform Programme. It must not be put to the country by the government, but by Parliament as a whole; and must not be put on the day of the General Election, where the unpopularity of the government could damage the referendum.

    “If passed, the new electoral system should be introduced for the election after next, with the Boundary Commission charged with drawing up the new larger constituencies and top-up areas (for additional members and Senators) in time.”

  6. I agree with Tom Round’s comment # 5, the point I was trying to make is that the functional difference between AV and FPTP is limited. Many voters under FPTP make their switch to their second choice before entering the polling booth.

    AV removes from the voters the burden of having to forecast the political situation in their district, which many voters simply can’t or won’t do. This is a good thing. But it seems to reduce the number of seats won by minor parties compared to FPTP, though this is based on the Australian experience and there could be a cultural issue there.

    I like AV+ better than I did before, its hard to justify theoretically but could work well in the British context. Just call the additional members “county members” and the members elected from the single member districts “borough members” and you even revive an old British tradition.

  7. It looks like the third party’s share is about 23%, not enough to make the cut. Duverger’s rather remarkable track record continues to hold up.

  8. A Con-Lib Dem coalition, with a commitment to a referendum on PR, might be better for reform in the long run, if the Tories are desperate enough to cave in on it.

    Firstly, the very fact that they can deal with the Lib Dems might reassure the Tories that they will not be irrevocably shut out of goverment with a preferential or proportional system.

    Secondly, even if as is likely the Tories will oppose PR in a referendum, the whole process will at least be free of the almost certainly fatal “losers trying to rig the next election” rhetoric that would inevitable if a Labour Lib Dem minority coalition introduced it.

    Thats not to say a Con-Lib coalition might not be objectionable for other reasons. Reformers need to remember that getting a referendum is not enough, they have to win it-ask the BC reformers!

  9. Pingback: UK 2015 forecasts | Fruits and Votes

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