Swing in a British political context is a single figure used as an indication of the scale of voter change between two political parties. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located It originated as a mathematical calculation for comparing the results of two constituencies. The term "swing" has a different meaning in Australia, which has a different voting system. For a topic outline on this subject see List of basic Australia topics. See Swing (Australian politics). The term swing is used in Australia in a different sense from that employed in Britain, where the term originated (see Swing (politics)

Electoral Swing Analysis

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.

An example is the comparison between the 2006 and 2007 Ukrainian Parliamentary elections. The Ukrainian parliamentary election took place on March 26, 2006. Early parliamentary elections in Ukraine took place on September 30, 2007.

Swing Analysis comparison Ukrainian Parliametary Elections 2006 to 2007:

The above charts show the change in voter support for each of the six major political parties by electoral district and nation wide vote results.

The data is derived from the official published election results.

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). Dr David Butler (born 17 October 1924) is a Social Scientist and Psephologist. There is an alternative version called Steed 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%.

Creation

Swing was originated by David Butler, a political science academic at Nuffield College, Oxford. Dr David Butler (born 17 October 1924) is a Social Scientist and Psephologist. Nuffield College is one of the constituent colleges of the University of Oxford in England. 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. The swingometer is a Graphics device that shows the swing from one party to another on British election results programmes

Problems and development

During the post-war period British politics was characterised by a strong two-party system. A two-party system is a form of Party system where two major Political parties dominate voting in nearly all Elections at every Almost all voters who changed their preference from one election to another, swung between one of the two parties. Although the majority still do, there has 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 plurality voting system is a Single-winner voting system often used to elect executive officers or to elect members of a legislative assembly which is based on single-member

The Liberals (and, later, Liberal Democrats) have been the main catalyst for this change, providing a centrist alternative to the two parties. The Liberal Party was one of the two major British political parties from the early 19th century until the rise of the Labour Party in the 1920s and a third party The Liberal Democrats, often shortened to Lib Dems, are a liberal Political party in the United Kingdom, formed in 1988 by merging the The situation has also changed due to the success of the SNP in Scotland and Plaid Cymru in Wales, especially in elections to the Scottish Parliament and Welsh Assembly. The Scottish National Party (SNP (Pàrtaidh Nàiseanta na h-Alba Scottis Naitional Pairtie is a Centre-left political party which campaigns for Scottish Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. Plaid Cymru (plaɪd ˈkəmri The Party of Wales often referred to simply as Plaid) is a Political party in Wales. The Scottish Parliament ( Scottish Gaelic: Pàrlamaid na h-Alba; Scots: Scottish Pairlament) is the devlolved national unicameral The National Assembly for Wales (Cynulliad Cenedlaethol Cymru is a devolved assembly with power to make legislation in Wales. Two other mass parties - the Green Party, which emerged in the 1980s, and UKIP, which emerged in the 1990s - have yet to win any seats in Parliament, but have had a significant effect on the swing in certain areas, most notably when the Greens took 22% of the vote in the Brighton Pavilion constituency in the 2005 general election. The Green Party of England and Wales (GPEW (Plaid Werdd Cymru a Lloegr is the principal Green political party in England and Wales. The United Kingdom Independence Party (commonly known as UKIP, ˈjuːkɪp Brighton Pavilion is a Constituency represented in the House of Commons of the Parliament of the United Kingdom. Results Overview For events leading up to the date of the election see article Pre-election day events of the United Kingdom general

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. Margaret Hilda Thatcher Baroness Thatcher LG, OM, PC, FRS (born 13 October 1925 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 often 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. The Press Association is the national News agency of the United Kingdom and Ireland supplying news wire to almost all national and local newspapers TV & radio news as well For this reason, the direction of swing is explicitly stated, rather than simply indicated through the sign as applies to Butler Swing.

Measurements

It should be noted that Butler Swings of over 10% in magnitude are very rare. Taking British 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% in magnitude, and that was -10. Results |} Total votes cast 24073025 All parties shown Conservative total includes Ulster Unionists Reason for Labour victory Results The election was fought under new boundaries with a net increase of eight seats compared to the 1992 election 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.

References

• The British General Election of 1945 by R. B. McCallum and Alison Readman (Oxford University Press, 1947) pages 263-5
• Political Change in Britain by David Butler and Donald Stokes (Macmillan, 1969) pages 140-51