The Mathematics of the General Election

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The Mathematics of the General Election

• Dr Justin Greaves
• Department of Politics
• University of Warwick

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Outline of this talk

• The basics (background and context)
• What is a swing?
• What is a hung parliament?
• The electoral system
• Opinion polls
• The national debt (perhaps the main election
  issue?)

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So, what are the basics?

• More than 45 million people aged 18 or above vote
  for a new Member of Parliament (MP) for the area
  in which they live (Constituency)
• Elections must be held at least every five years
  in Britain up to PM to choose the date
• Traditionally held on a Thursday

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Why a Thursday?

• One theory about its origins is that people were
  not paid until Fridays and so holding polls on
  Thursdays ensured they were not too drunk to vote

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Two controversial issues

1. Should the voting age be reduced to 16?
2. Should we introduce compulsory voting (as in
   Australia)?

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The three main parties
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The three party leaders

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The TV debates

• This is the first election in the UK where there
  have been TV debates between the three party
  leaders
• Here is a clip from the 2nd debate

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Too much celebrity?

• Is it becoming too much like the X Factor or
  Britains Got Talent?
• Leaders judged on how good they look on TV?

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So now onto the maths ....

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What is a swing?

• Swing is a tool which helps explain how elections
  are won and lost
• In simple terms it is a way of measuring how the
  public's support of political parties changes
  from one election to the next

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The calculation

• Step 1. Add the rise in one party's share in the
  vote to the fall in the second party's share of
  the vote.
• Step 2. Divide your figure by two. The resulting
  figure is the swing.

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An example

• In the 2005 General Election the Labour Party had
  a lead of 3 over the Conservative Party
• Lets assume that in Thursdays election, the
  result is a Con lead of 4 over Labour
• Exercise calculate the swing

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The answer

• This is a swing of 3.5 (34/2).

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What to look out for

• 1.6 swing against Labour Labour lose their
  overall majority
• 4.3 swing against Labour The Conservatives
  become the largest party. They would still not
  have an overall majority.
• 6.9 swing against Labour The Conservatives gain
  an overall majority and therefore form the next
  government
• (but will a UNS operate?)

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What is a hung parliament?

• If one party has an absolute majority it means
  that it has more seats than all the other parties
  put together (326)

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• If no party has such a majority then there is a
  hung parliament
• The smaller parties can then join forces to
  out-vote the government
• This makes it difficult to pass laws

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• There is a good chance of a hung parliament
  resulting from this election
• The last time it happened was in February 1974

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Options in a hung parliament

• Formal coalition (alliance with another party)
• Confidence and supply
• Minority government
• If none of these options work there would have to
  be another election

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Why is it so rare?

• Hung Parliaments and coalitions happen a lot in
  other countries
• So why are they so rare in the UK?
• This is mainly a result of our electoral system

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Proportional Representation

• Many countries have a proportional electoral
  system (eg under PR if a party wins 30 of the
  votes, it will win approx 30 of the seats)
• It is rare for any one party to get over 50 of
  the vote
• Therefore, in these countries parties will have
  to work together

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First past the post

• Britain has a first past the post electoral
  system
• Therefore, 650 constituencies
• In each one, the candidate who gets the most
  votes wins (even if it is less than 50)
• EG if the winner gets 36 of the vote they still
  take the seat

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• It is like a horse race
• The winner of the race is the first to pass a
  particular point on the track

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Strange results

• FPP can throw up strange results
• A party with 35/40 support can get well over 50
  of the seats
• The party that wins most votes may not win most
  seats (eg 1974)
• The Lib Dems could come first in vote share and
  third in seats

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Opinion polls

• You may have seen opinion polls in the media
• These may only interview 1000 people out of the
  whole population of Britain
• If the sample is representative these polls
  should be accurate

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• Polls usually have a margin of error of or 3
• 19 times out of 20 a poll should fall between
  this margin of error

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Think, pair, share

• What could cause an opinion poll to be biased or
  skewed in some way?

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National debt and borrowing

• One of the biggest election issue is the amount
  of money the government is borrowing (and
  Britains national debt)
• Due to the recession the government had to borrow
  a lot of money

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• One reason was to rescue the banks

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• Another was to pay benefits to those who became
  unemployed
• And if people are out of work the government also
  loses tax revenue

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Party Policy

• The Labour Party plans to reduce the amount we
  borrow by 50 over four years (starting in 2011)
• The Conservative Party say this is not enough.
  They want to go cut faster and deeper

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Debt statistics

• Borrowing of 163 billion last year
• The government forecasts that debt will soar to
  1.1 trillion by 2011

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Debt statistics (2)

• We owe 14,480 for every man, woman and child
• That's more than 31,254 for every person in
  employment
• Every household will pay 1,898 this year, just
  to cover the interest

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Thank you for listening