Swing (United Kingdom)
Encyclopedia
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.
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.
The swing is the percentage of voter support minus the comparative percentage of voter support corresponding to the same electorate or demographic.
Swing in a British
political context is a single figure 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 constituencies. Britain uses a First-past-the-post
voting system
.
Swing which calculates the percentages 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, if in the previous election Labour had 45%, the Conservatives 35% and the Liberal Democrats 20%, and in the new election the Conservatives had 45%, Labour had 40% and the Liberal Democrats 15%, then the Butler Swing would be the average of the Conservative gain (10%) and Labour loss (5%), which makes +7.5%.
The Steed Swing is slightly more complicated to calculate. Labour's 45% of the total vote is 56.25% of the combined Labour and Conservative vote in the previous election (that is, 45/(45+35)), and the Conservative's 35% equates to 43.75% (35/(45+35)). In the new election the revised percentages are 47.06% (40/(40+45)) and 52.94% (45/(40+45)) respectively. The Steed Swing is the percentage movement between the two parties, ignoring the other parties; this is +9.19%, which is arithmetically either the Conservative party's gain (9.19%, being 52.94% less 43.75%) or Labour's loss (also 9.19%, being 47.06% less 56.25%).
. 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 British General Elections are "marginal" 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.
. 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
electoral 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 Britain have become increasingly fractured. The general sense of national unity that existed in the post-war era began to fall apart in the 1970s and broke, apparently irrevocably, during Margaret Thatcher
's premiership . This has led to swings being very different in different areas - for instance, 1992 saw a swing to the Conservatives in Scotland, but a swing to Labour in the South East of 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.
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% in magnitude, and that was -10.23%. 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 over 10% in magnitude.
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.
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.
The swing is the percentage of voter support minus the comparative percentage of voter support corresponding to the same electorate or demographic.
Swing in a British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
political context is a single figure 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 constituencies. Britain uses a First-past-the-post
First-past-the-post
First-past-the-post voting refers to an election won by the candidate with the most votes. The winning potato candidate does not necessarily receive an absolute majority of all votes cast.-Overview:...
voting system
Voting system
A voting system or electoral system is a method by which voters make a choice between options, often in an election or on a policy referendum....
.
Original mathematical calculation
The original mathematical construct Butler Swing is defined as the average of the Conservative % gain and Labour % loss between two elections, with the percentages being 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 SteedMichael Steed
Michael Steed is a British psephologist, political scientist, broadcaster, activist and Liberal Democrat politician. He was born in 1940 in Kent, where his father was a farmer. He has written extensively on parties and elections....
Swing which calculates the percentages 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, if in the previous election Labour had 45%, the Conservatives 35% and the Liberal Democrats 20%, and in the new election the Conservatives had 45%, Labour had 40% and the Liberal Democrats 15%, then the Butler Swing would be the average of the Conservative gain (10%) and Labour loss (5%), which makes +7.5%.
The Steed Swing is slightly more complicated to calculate. Labour's 45% of the total vote is 56.25% of the combined Labour and Conservative vote in the previous election (that is, 45/(45+35)), and the Conservative's 35% equates to 43.75% (35/(45+35)). In the new election the revised percentages are 47.06% (40/(40+45)) and 52.94% (45/(40+45)) respectively. The Steed Swing is the percentage movement between the two parties, ignoring the other parties; this is +9.19%, which is arithmetically either the Conservative party's gain (9.19%, being 52.94% less 43.75%) or Labour's loss (also 9.19%, being 47.06% less 56.25%).
Creation
Swing was originated by David Butler, a political science academic at Nuffield College, OxfordNuffield College, Oxford
Nuffield College is one of the constituent colleges of the University of Oxford in England. It is an all-graduate college and primarily a research establishment, specialising in the social sciences, particularly economics, politics and sociology. It is a research centre in the social sciences...
. 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 British General Elections are "marginal" 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
Swingometer
The swingometer is a graphics device that shows the swing from one party to another on British election results programmes. It was invented by Peter Milne, and later refined by David Butler and Robert McKenzie....
' which consisted of a pendulum which could point to the swing nationally and illustrate the outcome.
Problems and development
During the post-war period British politics was characterised by a strong two-party systemTwo-party system
A two-party system is a system where two major political parties dominate voting in nearly all elections at every level of government and, as a result, all or nearly all elected offices are members of one of the two major parties...
. 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
First-past-the-post
First-past-the-post voting refers to an election won by the candidate with the most votes. The winning potato candidate does not necessarily receive an absolute majority of all votes cast.-Overview:...
electoral 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
Liberal Party (UK)
The Liberal Party was one of the two major political parties of the United Kingdom during the 19th and early 20th centuries. It was a third party of negligible importance throughout the latter half of the 20th Century, before merging with the Social Democratic Party in 1988 to form the present day...
(and, later, Liberal Democrats
Liberal Democrats
The Liberal Democrats are a social liberal political party in the United Kingdom which supports constitutional and electoral reform, progressive taxation, wealth taxation, human rights laws, cultural liberalism, banking reform and civil liberties .The party was formed in 1988 by a merger of the...
) have been the main catalyst for this change, providing a credible nationwide alternative to the two main parties. The success of the SNP
Scottish National Party
The Scottish National Party is a social-democratic political party in Scotland which campaigns for Scottish independence from the United Kingdom....
in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
and Plaid Cymru
Plaid Cymru
' is a political party in Wales. It advocates the establishment of an independent Welsh state within the European Union. was formed in 1925 and won its first seat in 1966...
in Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
, especially in elections to the Scottish Parliament
Scottish Parliament
The Scottish Parliament is the devolved national, unicameral legislature of Scotland, located in the Holyrood area of the capital, Edinburgh. The Parliament, informally referred to as "Holyrood", is a democratically elected body comprising 129 members known as Members of the Scottish Parliament...
and Welsh Assembly, has also had an effect. Two other mass parties - the Green Party
Green Party of England and Wales
The Green Party of England and Wales is a political party in England and Wales which follows the traditions of Green politics and maintains a strong commitment to social progressivism. It is the largest Green party in the United Kingdom, containing within it various regional divisions including...
, which emerged in the 1980s, and UKIP
United Kingdom Independence Party
The United Kingdom Independence Party is a eurosceptic and right-wing populist political party in the United Kingdom. Whilst its primary goal is the UK's withdrawal from the European Union, the party has expanded beyond its single-issue image to develop a more comprehensive party platform.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 Britain have become increasingly fractured. The general sense of national unity that existed in the post-war era began to fall apart in the 1970s and broke, apparently irrevocably, during Margaret Thatcher
Margaret Thatcher
Margaret Hilda Thatcher, Baroness Thatcher, was Prime Minister of the United Kingdom from 1979 to 1990...
's premiership . This has led to swings being very different in different areas - for instance, 1992 saw a swing to the Conservatives in Scotland, but a swing to Labour in the South East of 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
Press Association
The Press Association is the national news agency of the United Kingdom and Ireland, supplying multimedia news content to almost all national and regional newspapers, television and radio news, as well as many websites with text, pictures, video and data content globally...
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.
Measurements
Butler Swings of over 10% in magnitude are very rare. Taking British politics after 1945United Kingdom general election, 1945
The United Kingdom general election of 1945 was a general election held on 5 July 1945, with polls in some constituencies delayed until 12 July and in Nelson and Colne until 19 July, due to local wakes weeks. The results were counted and declared on 26 July, due in part to the time it took to...
exclusively (as that election occurred ten years after its predecessor, and in a completely different political climate), only the 1997 general election
United Kingdom general election, 1997
The United Kingdom general election, 1997 was held on 1 May 1997, more than five years after the previous election on 9 April 1992, to elect 659 members to the British House of Commons. The Labour Party ended its 18 years in opposition under the leadership of Tony Blair, and won the general...
had a national swing of more than 10% in magnitude, and that was -10.23%. 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 over 10% in magnitude.
| General election | National swing | 10% Swings to Labour | 10% Swings to Conservative |
|---|---|---|---|
| 1951 United Kingdom general election, 1951 The 1951 United Kingdom general election was held eighteen months after the 1950 general election, which the Labour Party had won with a slim majority of just five seats... |
+1.09 | 1 | - |
| 1955 United Kingdom general election, 1955 The 1955 United Kingdom general election was held on 26 May 1955, four years after the previous general election. It resulted in a substantially increased majority of 60 for the Conservative government under new leader and prime minister Sir Anthony Eden against Labour Party, now in their 20th year... |
+1.74 | - | - |
| 1959 United Kingdom general election, 1959 This United Kingdom general election was held on 8 October 1959. It marked a third successive victory for the ruling Conservative Party, led by Harold Macmillan... |
+1.12 | 3 | - |
| 1964 United Kingdom general election, 1964 The United Kingdom general election of 1964 was held on 15 October 1964, more than five years after the preceding election, and thirteen years after the Conservative Party had retaken power... |
–3.01 | 7 | - |
| 1966 United Kingdom general election, 1966 The 1966 United Kingdom general election on 31 March 1966 was called by sitting Labour Prime Minister Harold Wilson. Wilson's decision to call an election turned on the fact that his government, elected a mere 17 months previously in 1964 had an unworkably small majority of only 4 MPs... |
–2.7 | - | - |
| 1970 United Kingdom general election, 1970 The United Kingdom general election of 1970 was held on 18 June 1970, and resulted in a surprise victory for the Conservative Party under leader Edward Heath, who defeated the Labour Party under Harold Wilson. The election also saw the Liberal Party and its new leader Jeremy Thorpe lose half their... |
+4.81 | - | 4 |
| Feb. 1974 United Kingdom general election, February 1974 The United Kingdom's general election of February 1974 was held on the 28th of that month. It was the first of two United Kingdom general elections held that year, and the first election since the Second World War not to produce an overall majority in the House of Commons for the winning party,... |
–0.74 | 6 | 1 |
| Oct. 1974 United Kingdom general election, October 1974 The United Kingdom general election of October 1974 took place on 10 October 1974 to elect 635 members to the British House of Commons. It was the second general election of that year and resulted in the Labour Party led by Harold Wilson, winning by a tiny majority of 3 seats.The election of... |
–2.12 | - | - |
| 1979 United Kingdom general election, 1979 The United Kingdom general election of 1979 was held on 3 May 1979 to elect 635 members to the British House of Commons. The Conservative Party, led by Margaret Thatcher ousted the incumbent Labour government of James Callaghan with a parliamentary majority of 43 seats... |
+5.29 | - | 23 |
| 1983 United Kingdom general election, 1983 The 1983 United Kingdom general election was held on 9 June 1983. It gave the Conservative Party under Margaret Thatcher the most decisive election victory since that of Labour in 1945... |
+4.07 | - | 9 |
| 1987 United Kingdom general election, 1987 The United Kingdom general election of 1987 was held on 11 June 1987, to elect 650 members to the British House of Commons. The election was the third consecutive election victory for the Conservative Party under the leadership of Margaret Thatcher, who became the first Prime Minister since the 2nd... |
–1.75 | 6 | - |
| 1992 United Kingdom general election, 1992 The United Kingdom general election of 1992 was held on 9 April 1992, and was the fourth consecutive victory for the Conservative Party. This election result was one of the biggest surprises in 20th Century politics, as polling leading up to the day of the election showed Labour under leader Neil... |
–2.08 | 1 | 1 |
| 1997 United Kingdom general election, 1997 The United Kingdom general election, 1997 was held on 1 May 1997, more than five years after the previous election on 9 April 1992, to elect 659 members to the British House of Commons. The Labour Party ended its 18 years in opposition under the leadership of Tony Blair, and won the general... |
–10.23 | 364 | - |
| 2001 United Kingdom general election, 2001 The United Kingdom general election, 2001 was held on Thursday 7 June 2001 to elect 659 members to the British House of Commons. It was dubbed "the quiet landslide" by the media, as the Labour Party was re-elected with another landslide result and only suffered a net loss of 6 seats... |
+1.80 | - | - |
| 2005 United Kingdom general election, 2005 The United Kingdom general election of 2005 was held on Thursday, 5 May 2005 to elect 646 members to the British House of Commons. The Labour Party under Tony Blair won its third consecutive victory, but with a majority of 66, reduced from 160.... |
+3.15 | - | 2 |
| 2010 | +5.17 | - | 36 |
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.