Swing (United Kingdom)

Last updated

Swing, in the politics of the United Kingdom, is a number used as an indication of the scale of voter change between two political parties. It originated as a mathematical calculation for comparing the results of two Parliamentary constituencies. The UK uses a first-past-the-post voting system. The swing (in percentage points) is the percentage of voter support minus the comparative percentage of voter support corresponding to the same electorate or demographic.

Contents

The swing is calculated by comparing the percentage of voter support from one election to another. The percentage value of the comparative elections results are compared with the corresponding results of the substantive election. An electoral swing analysis shows the extent of change in voter support from one election to another. It can be used as a means of comparison between individual candidates or political parties for a given electoral region or demographic.

Original mathematical calculation

The original mathematical construct Butler swing is defined as the average of the Conservative Party percentage-point gain and Labour Party percentage-point loss between two elections, calculated on the basis of the total number of votes (including those cast for candidates other than Conservative or Labour). There is an alternative version called Steed swing which calculates the swing on the basis of votes cast for Conservative and Labour only. It is possible for the same election to have a Butler swing of one sign and a Steed swing of the other.

As an example, assume that a constituency had two sequential election results as follows:

PartyPrevious election (%)Current election (%)±
Conservatives3545+10
Labour4540−5
Liberal Democrats2015−5
Total100100

The Butler swing to the Conservatives is therefore:

The Steed swing is slightly more complicated to calculate, as it focuses on the shift between two specific parties (ignoring all others). In the above case, the swing to the Conservatives would be:

Labour would have a corresponding loss in the same amount:

Creation

Swing was originated by David Butler, a political science academic at Nuffield College, Oxford. In a contribution to The British General Election of 1945 he wrote "this measurement of 'swing', admittedly imperfect, does give us a broad idea of the movement of opinion from Conservative to Labour" and went on to compare the swings in each area of the country.

The concept became important in the general elections of the 1950s when it was found that there was a relatively uniform swing across all constituencies. This made it easy to predict the final outcomes of general elections when few actual results were known, as the swing in the first constituencies to declare could be applied to every seat.

Only a relatively small proportion of seats in most UK general elections are marginal seats, and thus likely to change party. The swing enabled prediction of outcomes to be made even while safe seats were returning results whose victors were not in doubt. In several elections, such as 1970, the swing correctly predicted a majority for the then opposition even while government party victories seemed to predominate.

Taking the national vote shares in an opinion poll could also easily be translated into likely seat outcomes. Election-night television programmes from 1955 have usually featured a device known as the "swingometer" which consisted of a pendulum which could point to the swing nationally and illustrate the outcome.

Problems and development

During the postwar period British politics was characterised by a strong two-party system. Almost all voters who changed their preference from one election to another, swung between the two main parties. There has been a much greater variety in change since the re-emergence of three-party politics in the 1970s. The original calculation of swing did not make any allowance for other parties and when the votes for other parties rose, demands arose for a more sophisticated measurement. The continuation of the first-past-the-post system, and the tendency for smaller parties to only run in some constituencies, made it increasingly difficult to use measures of swing to predict results.

The Liberals (and, later, Liberal Democrats) have been the main catalyst for this change, providing a credible nationwide alternative to the two main parties. The success of the SNP in Scotland and Plaid Cymru in Wales, especially in elections to the Scottish Parliament and Welsh Assembly, has also had an effect. Two other mass parties – the Green Party, which emerged in the 1980s, and UKIP, which emerged in the 1990s – won no seats in Parliament until the Greens took Brighton Pavilion in the 2010 general election, but have had a significant effect on the swing in certain areas, most notably the Greens in Brighton Pavilion.

Swing has also been complicated since the 1970s as the constituent areas of the UK have become increasingly fractured. This has led to swings being very different in different areas – for instance, 1992 saw a swing to the Scottish Conservatives in Scotland, but a swing to Labour in South East England.

At the same time, other parties began to win significant levels of representation in the House of Commons. This has led to swing becoming a measurement of the changes in votes of the two biggest parties in the constituency in question, rather than just Labour and the Conservatives.

Simply substituting the Liberal Party for the Labour Party in the calculation provides a measure of a 'swing between Conservative and Liberal'. However election results showed that this was not a useful predictor in seats which were being fought by these parties. It came to be used as a measure of the significance of the change of the vote. Almost all published election results are derived from the Press Association results service which in recent years shows the swing as between the two parties that came first and second, rather than strictly between Conservative and Labour. For this reason, the direction of swing is explicitly stated, rather than simply indicated through the sign as applies to Butler Swing.

Analysis of relative party strengths

As swing analysis can be applied to the results of any two parties relative to each other, it is possible to assess parties' relative strengths, as seen in analysis of the 2010 United Kingdom general election:

Measurements

Butler swings of more than 10 points are very rare. Taking UK politics after 1945 exclusively (as that election occurred ten years after its predecessor, and in a completely different political climate), only the 1997 general election had a national swing of more than 10 points (−10.23 points). The table below shows the national swing across Great Britain, and the number of individual constituencies out of more than 600 which had a swing of more than 10 points.

General electionNational swing (Lab to Con)>10-point swings to Labour>10-point swings to Conservative
1951 +1.091
1955 +1.74
1959 +1.123
1964 −3.017
1966 −2.7
1970 +4.814
Feb. 1974 −0.7461
Oct. 1974 −2.12
1979 +5.2923
1983 +4.079
1987 −1.756
1992 −2.0811
1997 −10.23364
2001 +1.80
2005 +3.152
2010 +5.1736
2015 −0.3517
2017 +1.8 [1] 12
2019

Conventional swing is much more volatile, and many more constituencies have large conventional swings. In addition, the conventional swing in a constituency where the top two candidates are not Conservative and Labour cannot be meaningfully compared with the national or regional swing.

See also

Related Research Articles

Plurality voting refers to electoral systems in which a candidate, or candidates, who poll more than any other counterpart, are elected. In systems based on single-member districts, it elects just one member per district and may also be referred to as first-past-the-post (FPTP), single-member plurality (SMP/SMDP), single-choice voting, simple plurality or relative majority. A system with elects multiple winners elected at once with the plurality rule, such as one based on multi-seat districts, is referred to as plurality block voting.

<span class="mw-page-title-main">1983 United Kingdom general election</span>

The 1983 United Kingdom general election was held on Thursday 9 June 1983. It gave the Conservative Party under the leadership of Margaret Thatcher the most decisive election victory since that of the Labour Party in 1945, with a majority of 144 seats.

<span class="mw-page-title-main">1970 United Kingdom general election</span>

The 1970 United Kingdom general election was held on Thursday 18 June 1970. It resulted in a surprise victory for the Conservative Party under leader Edward Heath, which defeated the governing Labour Party under Harold Wilson. The Liberal Party, under its new leader Jeremy Thorpe, lost half its seats. The Conservatives, including the Ulster Unionist Party (UUP), secured a majority of 30 seats. This general election was the first in which people could vote from the age of 18, after passage of the Representation of the People Act the previous year, and the first UK election where party, and not just candidate names were allowed to be put on the ballots.

<span class="mw-page-title-main">1964 United Kingdom general election</span>

The 1964 United Kingdom general election was held on 15 October 1964, five years after the previous election, and thirteen years after the Conservative Party, first led by Winston Churchill, had regained power. It resulted in the Conservatives, led by the incumbent Prime Minister Alec Douglas-Home, narrowly losing to the Labour Party, led by Harold Wilson; Labour secured a parliamentary majority of four seats and ended its thirteen years in opposition. Wilson became the youngest Prime Minister since Lord Rosebery in 1894.

<span class="mw-page-title-main">1950 United Kingdom general election</span>

The 1950 United Kingdom general election was the first ever to be held after a full term of Labour government. The election was held on Thursday 23 February 1950, and was the first held following the abolition of plural voting and university constituencies. The government's 1945 lead over the Conservative Party shrank dramatically, and Labour was returned to power but with an overall majority reduced from 146 to just 5. There was a 2.8% national swing towards the Conservatives, who gained 90 seats. Labour called another general election in 1951, which the Conservative Party won.

<span class="mw-page-title-main">1959 United Kingdom general election</span> 8th October 1959

The 1959 United Kingdom general election was held on Thursday, 8 October 1959. It marked a third consecutive victory for the ruling Conservative Party, now led by Harold Macmillan. For the second time in a row, the Conservatives increased their overall majority in Parliament, this time to a landslide majority of 100 seats, having gained 20 seats for a return of 365. The Labour Party, led by Hugh Gaitskell, lost 19 seats and returned 258. The Liberal Party, led by Jo Grimond, again returned only six MPs to the House of Commons, but managed to increase its overall share of the vote to 5.9%, compared to just 2.7% four years earlier.

<span class="mw-page-title-main">Swingometer</span>

The swingometer is a graphics device that shows the effects of the swing from one party to another on British election results programmes. It is used to estimate the number of seats that will be won by different parties, given a particular national swing in the vote towards or away from a given party, and assuming that that percentage change in the vote will apply in each constituency. The device was invented by Peter Milne, and later refined by David Butler and Robert McKenzie.

An electoral swing analysis shows the extent of change in voter support, typically from one election to another, expressed as a positive or negative percentage. A multi-party swing is an indicator of a change in the electorate's preference between candidates or parties, often between major parties in a two-party system. A swing can be calculated for the electorate as a whole, for a given electoral district or for a particular demographic.

<span class="mw-page-title-main">1921 Alberta general election</span>

The 1921 Alberta general election was held on July 18, 1921, to elect members to the 5th Alberta Legislative Assembly. It was one of only five times that Alberta has changed governments.

<span class="mw-page-title-main">Oxford East (UK Parliament constituency)</span> Parliamentary constituency in the United Kingdom

Oxford East is a constituency represented in the House of Commons of the UK Parliament by Anneliese Dodds of the Labour Party, who also serves as party chair.

<span class="mw-page-title-main">Boston and Skegness (UK Parliament constituency)</span> Parliamentary constituency in the United Kingdom

Boston and Skegness is a county constituency, represented in the House of Commons of the UK Parliament. It is located in Lincolnshire, England. Like all British constituencies, Boston and Skegness elects one Member of Parliament (MP) by the first-past-the-post system of election. The seat has been represented by the Conservative MP Matt Warman since the 2015 general election, and is usually considered a safe seat for the party.

<span class="mw-page-title-main">Hornsey and Wood Green (UK Parliament constituency)</span> Parliamentary constituency in the United Kingdom, 1983 onwards

Hornsey and Wood Green is a constituency created in 1983 represented in the House of Commons of the UK Parliament since May 2015 by Catherine West, of the Labour Party. To date it has drawn together for general elections parts of the London Borough of Haringey.

<span class="mw-page-title-main">Harrow West (UK Parliament constituency)</span> Parliamentary constituency in the United Kingdom, 1945 onwards

Harrow West is a constituency in Greater London created in 1945 and represented in the House of Commons of the UK Parliament. Until 1997, it only returned Conservative MPs; since then, it has elected the Labour Co-operative MP Gareth Thomas on a fluctuating majority. Since 2010, this has been bolstered by the loss of Pinner from the seat and the gain of a favourable ward for Labour from Harrow East.

<span class="mw-page-title-main">2005 United Kingdom general election</span>

The 2005 United Kingdom general election was held on Thursday 5 May 2005, to elect 646 members to the House of Commons. The Labour Party, led by Tony Blair, won its third consecutive victory, with Blair becoming the second Labour leader after Harold Wilson to form three majority governments. However, its majority fell to 66 seats compared to the 167-seat majority it had won four years before. This was the first time the Labour Party had won a third consecutive election, and remains the party's most recent general election victory.

<span class="mw-page-title-main">2010 United Kingdom general election</span> General election held in the United Kingdom

The 2010 United Kingdom general election was held on Thursday 6 May 2010, with 45,597,461 registered voters entitled to vote to elect members to the House of Commons. The election took place in 650 constituencies across the United Kingdom under the first-past-the-post system.

Elections to the Borough Council in Slough, England, were held on 1 May 2008. This was the 123rd Slough general local authority election since Slough became a local government unit in 1863.

An election for the Borough Council in Slough, England, was held on 6 May 2010. This was the 124th Slough general local authority election since Slough became a local government unit in 1863.

In the run up to the general election of 2005, several polling organisations carried out opinion polling in regards to voting intention in Great Britain. Results of such polls are displayed below.

<span class="mw-page-title-main">2015 United Kingdom general election</span> General election held in the United Kingdom

The 2015 United Kingdom general election was held on Thursday, 7 May 2015 to elect 650 members to the House of Commons. It was the first and only general election held at the end of a Parliament under the Fixed-term Parliaments Act 2011. Local elections took place in most areas on the same day.

Opinion polling for the next United Kingdom general election has been carried out by various organisations to gauge voting intention. Most of the polling companies listed are members of the British Polling Council (BPC) and abide by its disclosure rules. The dates for these opinion polls range from the 2019 United Kingdom general election on 12 December to the present day.

References

  1. Travis, Alan (9 June 2017). "The youth for today: how the 2017 election changed the political landscape". The Guardian. ISSN   0261-3077 . Retrieved 30 June 2020.