UK election 2017-any hope for electoral reform?

One of the most remarkable things about the UK election was the total number of votes cast for the top two parties, which increased from 67.3% in 2015 to 82.8% this year. It has been less noticed, however, that this has come with a substantial drop in the Gallagher (least squares) Index of disproportionality. From 15.02 in 2015, it has more than halved to 6.41, a figure actually larger than that in Ireland in 2011, Germany in 2013, or Poland in 2015.

Source: Michael Gallagher

This is largely due to the absence of a large third party discriminated against by the single-seat plurality system. No established minor party outside Northern Ireland gained votes, with UKIP and the Greens both falling to below 2% and even the Liberal Democrats slipping back slightly in terms of votes despite picking up four seats. The (unusual, as Shugart points out) absence of an unearned majority for either party also contributed to the low score.

There also seems to be some evidence from past UK election results that two-party elections tend to be more proportional. Between the 1950 and 1970 elections, when support for the Liberals (the only substantial third party) never exceeded 11.2% (and was generally substantially below this), the Gallagher Index averaged only 6.41; since then, with the until-recent presence of the SDP-Liberal Alliance/Liberal Democrats, it has stayed high as can be seen above.

The number of very marginal seats has also increased substantially at this election, as can be seen above. While other readers may disagree with me on this, I personally view a higher number of marginals as good for the status quo, given that it means more voters view their votes as having an impact upon the result. This is not necessarily a result that would appeal to the major parties, but it would seem to act to quell public concern over the current system.

The growth of the top two creates a problem for electoral reform advocates. Which party, exactly, benefits from implementing proportional representation? The Labour and Conservative parties obviously have no personal interest in PR. The Liberal Democrats, at present, are far too weak to extract such a concession (even with 57 seats in 2010, the best they could do was a referendum on AV) in a coalition, as are the Great British regionalist parties (which would probably be heavily expected to go with Labour anyway, weakening their leverage) and the Greens (much the same reason).

Labour’s manifesto makes no specific mention of proportional representation, while the Conservative manifesto goes further, calling for single-seat plurality to be adopted for mayoral and Police and Crime Commissioner elections. Shadow Chancellor John McDonnell has gone on record in the past as being in favour of proportional representation, but I suspect now Labour are at 40% that proposal will be soon forgotten.

While the past two months has demonstrated conclusively that much can change in a short time in UK politics, it’s difficult to imagine that proportional representation could gain any traction in a political system dominated by the top two parties after failing to gain traction (at least for the House of Commons) in nearly thirty years of three-party politics.

The UK 2017 result–Comparative data forays

Well, the election that I thought would be just a boring “typical” snap election in which the incumbent takes advantage of the unprepared opposition… did not quite turn out that way.

Some things happened that are not supposed to happen. And some things about the result are glaringly off the mark of what we should expect from the Seat Product Model (which, of course, is meant to predict average trends, not individual elections).

Top two dominance but no majority

A party is not supposed to gain votes, but lose seats. It is hard to exaggerate how extraordinary this is. The top two parties combined for 82.4% of the votes, the highest in the UK in a long time. The last time it was over 80% was in 1979. The last time over 75% was 1992, and in the three elections immediately before this one, the future had been around two thirds.

Yet, despite the recovery of the top-two vote shares, there is no majority party. Parliamentary majorities have been won on far less in the past, and one would not expect such dominance of the two leading parties (42.4% and 40.0%) under FPTP to fail to produce majority government. But here we are.

I was curious to know just how common it was for both parties in a FPTP parliamentary system to have at least 40% of the vote, but there to be no parliamentary majority. In my dataset of FPTP elections, consisting of 210 observations, I find one case: Trinidad and Tobago 1995 (two top parties on 48.8% and 47.2%, tied in seats with 17/36). (I have not kept this updated in recent years, and perhaps I am failing to remember one that would be included if I had.)

If I drop my threshold a little lower, to the top two parties both being at at least 38% (but no seat majority), I get one more case: Canada 1957. Of course, the main reason why a leading party with 40% or even 38% of the votes so often gets a majority under FPTP is that it tends to have a more substantial lead over the runner-up, implying many districts are competitive.

Thus it is not only the top two absolute sizes that matter for getting a majority, but also their ratios. How common is it for the top two parties to have votes so similar? First of all, let’s define a ratio of the top two in votes; the mean of this ratio in the data sample is 1.67 (median 1.26). In this UK election, it was 1.06. Approximately 15% of the elections are this close. However, only around 3% of all the elections are both this close and result in no majority party, including UK 1974 (Feb.).

Thus the UK17 combination of two-party dominant, close, and no seat majority is pretty unusual!

Campaigns and leaders

Campaigns and leaders matter. That is not in itself surprising, but many political scientists (sometimes including me) consider them less important than “fundamentals”–whatever those might be. But May did not look like someone who could provide “strong and stable” government. And indeed, she may not get to provide any government at all, if she can’t survive a seemingly inevitable challenge to her position from within.

On the other hand, does Labour’s success relative to low expectations suggest leaders do matter? Did voters actually come to like Corbyn? I am aware of no evidence that such was the case. I suspect he was still a drag on the party, but will leave it to other analysts to try to sort this out. It seems to me that any reasonably competent Labour leader could have won this election, which in turn would never have happened, because May would not have called it had the main opposition had a reasonably competent leader.

The numbers compared Seat Product expectations

On the quantitative indictors, the effective number of vote-earning parties (N_V) was, by my calculations from data at BBC, 2.88. The last time it was that low in the UK was 1987, when the leading party (Conservative) won a vote share about the same as this time (42.3%), but it won 57.8% of the seats.

The effective number of seat-winning parties (N_S) was 2.47. This is not so unusual, by UK standards, as the figure was 2.53 in the 2015 election and 2.57 in 2010, the last time no party won a majority. In fact, the UK has tended to have a less fragmented parliamentary party system than expected from the Seat Product Model, which would be N_S=2.94. The maximum observed since 1945 was the just-reported 2.57 in 2010.

For N_V, the Seat Product Model says to expect 3.32, based solely on the large assembly size. Although the post-WWII mean is much lower than that, the electoral party system was finally behaving in the 1992-2015 period, with all those elections seeing N_V>3, and the last three (2005, 2010, 2015) all being at 3.6 or higher. Then came 2017, and the party system stopped behaving properly!

It should be emphasized that the Seat Product Model does not expect a majority party; with this large an assembly, even FPTP “should have” a largest party size of 44.5%. At 48.9%, the Conservatives are only a little higher than where they should be. But, of course, actual UK experience usually returns a majority in parliament, and this election was certainly expected to do so–where those expectations are based on political factors and the opinion polls, not the humble Seat Product Model.

Governance and policy

As for government-formation, clearly it is a Tory minority government. Claims by a few pundits that Corbyn could somehow assemble parliamentary support are pure fantasy. And there almost certainly won’t be a coalition. The most likely formula is backing from the Democratic Unionist Party (DUP), of Northern Ireland. The DUP’s 10 seats plus the Conservatives’ 318 combine for just over half the seats.

What will it mean for policy, especially Brexit? I can’t claim to know! But the DUP does not want a “hard border” with the Republic of Ireland, and that implies a “softer” Brexit. On the other hand, if the main motivation May had in calling the election was to boost her standing against restive members of her own caucus who want a harder Brexit, she failed. It will not be easy governance or policy-making for May or an intraparty successor.

Funny how elections don’t always turn out how we expect them to. Democracy! FPTP!

Appendix: Effective Number of Parties and the Seat Product Model

The effective number of parties is a size-weighted count, where each party’s share (of votes or seats) is weighted by itself through squaring. The squares are summed, and you take the reciprocal. See Michael Gallagher’s excellent website for details.

I am not going to explain here the logic behind the Seat Product Model. For that, see Taagepera (2007) or Li and Shugart (2016), or the forthcoming Shugart and Taagepera book, Votes from Seats (2017, due out in October). But the equations are as follows, where M is the mean magnitude (1, in the case of FPTP) and S is the assembly size (650 in recent UK elections).

N_S=(MS)^1/6;

N_V=[(MS)^1/4+1]^2/3;

Seat share of the largest party: s₁=(MS)^-1/8.

The important thing to understand about these equations is that they are not post-hoc regression fits. They are logical models, derived without reference to the data. When tested against the data from hundreds of democratic elections under various electoral systems, they are astonishingly accurate.

Related earlier posts and comment threads:

UK 2017: Green Party won’t stand in Ealing constituency

So much for fixed terms

UK 2015 and Diverter’s Law

Does UK 2015 mean the death knell for Duverger’s Law?

UK 2017

(Tempted to make that subject “UK 2017a”)

Yes, there should have been an open thread earlier. This comes late, but at least it’s here.

Quite an election surprise!

UK 2017: Green Party won’t stand in Ealing constituency

Here is something we do not see in First-Past-the-Post elections* as much as the Duvergerianists seem to think we should: one party agreeing not to have a candidate in order to avoid vote-splitting in a district.

The Green Party has pulled out of a crucial election seat in a bid to help the Labour Party beat the Tories – the first tactical withdrawal of its kind ahead of the general election.

The decision is expected to allow more votes to go to Labour MP Rupa Huq, who beat the Conservatives with a majority of just 274 votes in 2015, when no other party managed to attract more than seven per cent of the vote.

Green Party members in Ealing — where the party won 1,841 votes in the 2015 election — voted not to field a candidate last week, after Ms Huq promised to campaign for voting reform and the environment.

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* Except in India!

So much for fixed terms

Barring a further unexpected turn of events, it seems the UK government has an answer to the question of whether an early election can be called, despite the Fixed Term Parliaments Act. [Update: the measure to call the election has passed.]

Prime Minister Theresa May has indicated that she wants a snap election. In May, of course–Alas, no, it is actually on 8 June.

Under the FTPA, parliament can be dissolved early only if (1) the government loses confidence and a resolution of confidence in a government (whether the original or a new one) is not passed within 14 days, or (2) the House of Commons votes by two-thirds of its total number to dissolve itself.

May is seeking the latter, and with opposition Labour leader Jeremy Corbyn saying he “welcomes” an election, the vote is likely to go ahead.

May’s Conservatives have a narrow majority in the current Commons. The snap election is likely to give the party a much bigger one. This may not do much to strengthen the government’s hand with the EU in Brexit negotiations (the ostensible justification), but it should strengthen its hand against its own back-benchers.

Recommended: Alan Renwick’s take.

‘MP not 4 sale’

I am looking through my photo archives to see if I have anything that would be good for a book cover. The one below is a favorite, although not likely to make the grade as a cover image. It is the office front of the campaign of Tamsin Osmond in the constituency of Hampstead & Kilburn, UK, just before the 2010 election. The office was located on Finchley Rd. at Frognal. Across the street was a billboard for David Cameron and the Conservative Party, reflected in the office window.

The posters on the door are interesting. One refers to Osmond as “The election’s most enthusiastic candidate” and the other says “party politics is dead.”

The constituency was a three-way marginal in 2010. In fact, that was one of the reasons for choosing to stay there. We rented an apartment (at the Langorf–Frognal spelled backwards). An advantage of staying in a short-term rental rather than a hotel during an election campaign is you get campaign flyers through the mail slot! Such as this one:

We also obtained this very optimistic one.

Optimistic, but not absurdly so, at the time. The weeks we spent in the UK were the height of “Cleggmania” and if the LibDems were going to make the breakthrough that some polls hinted could be coming, Hampstead & Kilburn was the sort of place in which they were likely to be winning. And the Conservatives were worried. Note how Philp’s flyer points out how far behind the LibDems were in the local elections (upper right of front) and thus they “can’t win”; thus only the Conservatives can beat Labour in this constituency. On the lower right of the flip side, “vote LibDem, get Gordon” Brown (the Labour leader and incumbent PM).

In the election, Osmond won 123 (presumably most enthusiastic) votes. The incumbent MP, Glenda Jackson (the actress) was reelected with 32.8% of the vote and a margin of 42 votes (yes, forty two) over Philp. The margin over the third place candidate, the LibDem, was 841 votes. A Green Party candidate had 759 votes, just short of the total votes separating first from third. In addition to Osmond, there three other candidates (including one each from the BNP and UKIP) combining for 827 votes. It was quite an interesting constituency!

Other reasons for staying there: It was close to a stop on the express bus to Luton, where we were catching our El Al flight to Israel a few days after the election. It was also walking distance to a fascinating synagogue* (which we attended for Shabbat), which also happened to serve as the local polling station.

Sign to the polling station in front of the church on Belsize Square. The synagogue where the polling took place (and which I was able to spend a few minutes in on election day) is just past the church.

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* Note that “helping out on Mitzvah Day 2009” is among Chris Philp’s demonstrations of his local leadership. The constituency includes one of London’s major Jewish communities.

Brexit vs. BC-STV: Help with my principles!

As I noted earlier, I happened to be in British Columbia while the British were voting to leave the EU.

[Note: If you want to make general comments on Brexit and what happens next, please comment at the earlier thread. I’d like to keep this one on the narrower topic raised here.]

I never liked the BC-STV vote having been “defeated” in 2005 despite a clear majority (57%), due to a threshold of 60% having been set. But I do not like the UK “mandate” to leave the EU by a vote of 51.9%.

Is there a principle that reconciles my two positions? Or do I just have no principles regarding referendums*, and assess the rules for passage by whether I like what is being proposed? Help, please!

(I have written about referendum approval thresholds before.)

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* Other than that, in general, I’d rather not have them. I rather like representative democracy and deliberative institutions.