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The Mathematics of the General Election Dr Justin Greaves Department of Politics University of Warwick

The Mathematics of the General Election Dr Justin Greaves Department of Politics University of Warwick

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The Mathematics of the General Election

Dr Justin Greaves

Department of Politics

University of Warwick

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?)

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

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

Two controversial issues

1. Should the voting age be reduced to 16?

2. Should we introduce compulsory voting (as in Australia)?

The three main parties

The three party leaders

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

Too much celebrity?• Is it becoming too

much like the X Factor or Britain’s Got Talent?

• Leaders judged on how good they look on TV?

So now onto the maths ....

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

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.

An example

• In the 2005 General Election the Labour Party had a lead of 3% over the Conservative Party

• Let’s assume that in Thursday’s election, the result is a Con lead of 4% over Labour

• Exercise: calculate the swing

The answer• This is a swing of

3.5% (3+4/2).

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?)

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+)

• 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

• There is a good

chance of a hung parliament resulting from this election

• The last time it happened was in February 1974

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

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

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

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

• It is like a horse race• The winner of the

race is the first to pass a particular point on the track

Strange results

• FPP can throw up strange results:

1.A party with 35/40% support can get well over 50% of the seats

2.The party that wins most votes may not win most seats (eg: 1974)

3.The Lib Dems could come first in vote share and third in seats

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

• Polls usually have a

margin of error of + or – 3%

• 19 times out of 20 a poll should fall between this margin of error

Think, pair, share• What could cause

an opinion poll to be biased or skewed in some way?

National debt and borrowing• One of the biggest

election issue is the amount of money the government is borrowing (and Britain’s national debt)

• Due to the recession the government had to borrow a lot of money

• One reason was to

rescue the banks

• Another was to pay

benefits to those who became unemployed

• And if people are out of work the government also loses tax revenue

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

Debt statistics• Borrowing of £163

billion last year• The government

forecasts that debt will soar to £1.1 trillion by 2011

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

Thank you for listening