Electoral Systems - Basics

Where is it used?

• General elections
• Presidencial elections

What type of system is it?

• Majoritarian
• Plurality

How does it work?

• Voters select one candidate available on the ballot box to become their MP
• The candidate with more votes than anybody else wins the seat
• The party who ends up with a majority of the seats comes into power
• If no majority is won, a coalition forms between the two most successful parties (rarely happens under this electoral system)

Where is it used?

• All elections in Republic of Ireland (except presidencial & by-elections)
• House of Commons Speaker elections
• Northern Ireland Assembly

What type of system is it?

• Proportional
• Preferencial

How does it work?

• Voters rank candidates in order of preference
• To win, candidates must meet a threshold, determined by the number of seats available
• If the voter's first choice doesn't have enough votes, the vote is given to the second choice
• If the second choice doesn't have enough votes, the vote is given to the third choice, and so on
• This continues until the threshold is met
• This process repeats until all of the seats have been filled

Where is it used?

• Party leadership elections
• Irish presidential elections

What type of system is it?

• Preferencial

How does it work?

• Voters rank candidates in order of preference
• Any candidate who wins more than half of the overall votes as 1st preference wins outright
• If not, the candidate with the least 1st preferences is eliminated - the votes of anybody who ranked them as 1st preference will go to their 2ns preferences
• This continues until one candidate has half of the votes and is elected

Where is it used?

• Scottish Parliament
• Welsh Assembly

What type of system is it?

• Hybrid (proportional & majoritarian)

How does it work?

• Voters each get 2 votes - one for a candidate, one for a party
• Each constituency firstly returns one representative, elected by first past the post
• The votes for the party list candidates are then used to top up the seats won by each party
• This increases the proportionality; these extra winning candidates are the additional members

Where is it used?

• Mayor elections
• Police & crime commissioners (England & Wales)

What type of system is it?

• Preferencial

How does it work?

• Voters can pick up to 2 choices, ranked in order of preference
• All 1st choice votes are counted first - if a candidate wins a majority, they are elected
• If nobody wins a majority, the 2 most successful candidates stay in and the other candidates are eliminated from the process
• The 2nd choice votes of the eliminated candidates are counted
• Any votes for the remaining candidates are added to their totals
• After their 2nd choice votes have been counted, the candidate who ends up with the most votes wins

Where is it used?

• London borough elections
• National assembly elections in some countries

What type of system is it?

• Plurality

How does it work?

• As they are used in multi-member constituencies, voters can choose as many candidates as there are seats available
• More than one representative can be elected into each constituency
• The candidates with the most votes win - even if they didn't win a majority