Party-list proportional representation

Poster for the European Parliament election 2004 in Italy, showing party lists

Party-list proportional representation systems are a family of voting systems emphasizing proportional representation (PR) in elections in which multiple candidates are elected (e.g. elections to parliament). They can also be used as part of mixed additional member systems.

In these systems, parties make lists of candidates to be elected, and seats get allocated to each party in proportion to the number of votes the party receives. Voters may vote directly for the party, as in Israel, for candidates and that vote will pool to the party, as in Turkey and Brazil, or for a list of candidates, as in Hong Kong.

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The order in which a party's list candidates get elected may be pre-determined by some method internal to the party or the candidates (a closed list system) or it may be determined by the voters at large (an open list system).

Many variations on seat allocation within party-list proportional representation exist. The three most common are:

• The D'Hondt method (or Jefferson's method), used in Albania, Austria, Croatia, Estonia, Finland, Israel, Poland, Scotland and Spain, among other places;
• The Sainte-Laguë method (or Webster's method), used in many Scandinavian countries, New Zealand, and the German state of Bremen;
• The largest remainder (LR) methods, including the Hamilton method.

List proportional representation may also be combined in various hybrids, e.g. using the additional member system.

List of main apportionment methods (most proportional to least proportional):

• LR-Hare, unmodified Sainte-Laguë method (slightly favor very small parties if there is no election threshold)
• LR-Droop (slightly favors larger parties)
• D'Hondt method (slightly favors larger parties)
• LR-Imperiali (greatly favors larger parties)

While the allocation formula is important, equally important is the district magnitude (number of seats in a constituency). The higher the district magnitude, the more proportional an electoral system becomes - the most proportional being when there is no division into constituencies at all and the entire country is treated as a single constituency.

See also

• List of democracy and elections-related topics
• List MP
• Ley de lemas
• Legislative Council of Hong Kong
• Sectoral representation in the House of Representatives of the Philippines

External links

• Advantages and disadvantages of List PR - from the ACE Project
• Open, Closed and Free Lists - from the ACE Project
• Handbook of Electoral System Choice
• Apportionment, or How to Round Seat Numbers
• Glossary of Electoral Formulas