The following description is copied from the BC Citizens’ Assembly: Fact Sheet #10 – Proportional Representation – List Systems
Proportional Representation – List Systems
Proportional representation systems vary widely but all are designed to ensure that the range of opinion in the legislature reflects the range of opinion in the electorate. These systems distribute seats in proportion to the share of the vote received by each party or candidate.
Any PR system has three key elements – and it is in the details of these elements that PR systems vary so widely.
- Ballot structure
- District magnitude
- Electoral formula
There are two major types of proportional representation systems:
- PR – List Systems
- PR by the Single Transferable Vote (PR-STV)
Proportional representation list systems (PR-List)
Ballot structure
In PR-List systems, each party offers voters a list of candidates for election and voters select between party lists.
There are two types of lists – closed or open.
Closed Lists – Voters cast their ballot for the party of their choice and candidates are elected in the order they appear on the list – which is determined by the party. So candidates listed at the bottom of the list are less likely to be elected than those at the top. Closed lists allow party officials control over who gets elected and their subsequent political careers.
Open Lists – Voters are able to indicate on the ballot which candidate(s) they prefer on the list. The variations of open lists include:
- Voters may vote for either the party or a candidate – and can thus potentially influence which individuals on a list are elected (as is the case in Belgium)
- By voting for a candidate, voters signal their choice of parties and also which candidate from the party list they wish to elect (as in Finland)
- Voters are given more than one vote and can, thus, spread support among parties and candidates (as in Switzerland)
District Magnitude
District magnitude refers to the number of representatives – or seats – in a district. In PR systems, the DM can vary from two seats to the total seats in the Legislative Assembly. In the Netherlands, for example, the entire nation is one district. When there is more than one district, the DM – or number of seats in any given district – can vary from district to district. Higher DMs lead to more proportional outcomes.
Electoral Formula
Various mathematical formulas are used for allocating seats in proportion to votes – with decidedly different results. Many PR systems establish a Threshold, or minimum percentage of the vote that a party needs before it is entitled to any share of the seats. Typically, thresholds are in the 2-5% range. Occasionally, different formulas are used at different levels – or tiers – in determining seat allocation.
Largest Remainder Formula – These formulas involve establishing a Quota to determine how many votes it takes to win a seat. The votes a party wins is then divided by the quota to get the number of seats it is entitled to. If there is a seat left over, then the party with the largest number of remainder (unused) votes gets the seat.
Highest Average Formula – These formulas involve dividing the votes won by each party by some number and giving the party with
These calculations do not involve quotas.
Designing a PR system involves making a series of choices, including:
- Ballot Structure – Should party lists be open or closed?
- District Magnitude – How many districts? What size? How many seats in each?
- Formula – What formula should be used? Should there be a threshold?
Depending on the answers to the district magnitude and formula questions, the proportionality of the electoral system will vary. The nature of the candidate lists on the ballot will determine who has control over which candidates are elected, the parties or the voters.
The following description is copied from the Electoral Reform Society – UK
Party List PR
How does Party List Proportional Representation (PR) work?
There are two different types of Party List PR, Closed List and Open List.
In both cases parties present lists of candidates and seats are awarded according to their party’s share of the vote. This is usually done using an electoral formula or a quota which prevents too many small parties from winning seats.
Open List: Voters choose individual candidates from the list provided by each party and individual candidates are elected according to the popular vote.
Closed List: Voters vote for the party and therefore the list as a whole. Candidates are elected in the order they appear on the list (as decided by the party) until all the seats have been filled.
Semi-Open Lists: This gives voters some influence over who is elected, but most of the candidates will be elected in list order.
Pros and cons of Party List PR
The case for Party List PR
Party-list systems guarantee a high degree of party proportionality
Every vote has equal value.
It couldn’t be simpler: Voters have to make one choice out of a small selection.
List systems tend to involve large multi-member constituencies, which give more opportunities for women and minority groups to gain representation.
Open lists offer voters more choice and control over who is elected.
Closed lists are more amenable to measures that can increase the representation of women, such as gender quotas.
The arguments against Party List PR
Closed party lists are completely impersonal, weakening any link between the representative and a regional area.
Closed party lists offer very little in the way of voter choice: all the power, save that of choosing a party for government, resides with the party leaders.
As candidates are selected by the party leaders, they are likely to put ‘safe’ candidates near the top of the list, at the expense of traditionally under-represented groups.
Also with Closed party lists parties can stifle independent and minority opinion within their ranks. As all the power over who gets seats lies with the party machine, so too does the power to voice opinions.
Party lists discriminate against those not willing to be part of the party structure, and it is difficult to stand as an independent candidate.
Highly proportional systems with minimal thresholds can result in a fragmented parliament, and produce unstable, multi-party governments.