Party-list proportional representation

In party-list proportional representation (list PR) voters choose primarily between parties, and seats in a multi-member district are distributed among parties in proportion to their votes. Each party presents a ranked list of candidates; the seats a party wins are filled from its list. List PR is the most common electoral system for national legislatures in Europe and Latin America, and in various forms is used in dozens of countries worldwide.

Three design questions shape any list system:

1. District magnitude: how many seats per district. The Netherlands and Israel elect their whole parliament in a single national district; Spain uses provinces with very different magnitudes.
2. Allocation formula: how votes become seats. The D'Hondt divisor method slightly favours larger parties; Sainte-Laguë is closer to neutral; largest-remainder methods with a Hare quota favour small parties.
3. List type: in closed lists voters cannot change the order of candidates; in open lists preference votes determine who is elected; flexible lists combine the two.

Most systems add a legal threshold below which parties win no seats.

The core normative claim is fairness between parties: a parliament should mirror the distribution of political preferences, so that a party with 20% of the vote receives about 20% of seats. This contrasts with plurality systems, in which a party can win a majority of seats with a minority of votes.

Comparative political science associates list PR with several systematic effects:

• More parties. Duverger's law and its refinements predict that PR sustains multiparty systems, while single-member plurality tends to produce two main parties.
• Coalition government. Single-party majorities are rare, so governments are negotiated after elections. Lijphart's "consensus democracy" model links PR with power-sharing, broad coalitions and, he argues, better outcomes on representation of women and minorities and on voter satisfaction.
• Redistribution. Iversen and Soskice argue that PR systems tend to produce centre-left coalitions and more redistribution than majoritarian systems.
• Party discipline. Closed lists give party leaders power over candidates' careers, strengthening cohesion but weakening the personal link between representatives and voters.

Allocation methods compared

Disproportionality is commonly measured with the Gallagher index, the square root of half the sum of squared differences between vote and seat shares.

• Belgium, 1899. Belgium became the first country to use list PR for national parliamentary elections, adopting D'Hondt's method by a law of December 1899, after unrest and pressure for electoral reform. The ruling Catholic party, which dominated under the majority system, lost seats at the first PR election, a case often studied as a puzzle of self-limiting reform.
• The Netherlands. Since 1918 the lower house (150 seats since 1956) has been elected in effect as one national district with no legal threshold beyond the electoral quota of one seat (about 0.67% of the vote). This produces highly proportional results and fragmented parliaments in which many parties win seats.
• Israel. The Knesset is elected in a single national district by closed lists. The threshold was raised in stages, to 3.25% in 2014. Repeated inconclusive elections, five between 2019 and 2022, illustrate the coalition-formation difficulties of fragmented systems.
• Nordic open lists. Finland uses mandatory preference votes: voters choose a single candidate, whose vote also counts for the party, so intra-party competition is intense.
• Thresholds. Turkey's 10% threshold (in force from the 1980s until it was lowered to 7% in 2022) was among the highest in the world and left large shares of voters unrepresented in some elections.
• Mixed systems. List PR is a component of mixed-member proportional systems such as Germany and New Zealand, where list seats compensate for single-member district results.

• Weak local link. With large districts or closed lists, voters cannot hold an individual representative to account and may not know who represents them.
• Party oligarchy. Closed lists concentrate power in party leaderships, which control nomination and ranking.
• Fragmentation and instability. Low thresholds can produce many small parties, lengthy coalition negotiations and kingmaker roles for small parties. Defenders reply that coalition bargaining reflects genuine diversity and that many PR countries have stable governments.
• Accountability for governments. Because governments form after the election, voters cannot directly "throw the rascals out"; the same parties can remain in government in different combinations.
• Thresholds as a hidden majoritarian element. High thresholds waste votes and can produce results close to those of majoritarian systems.
• Extremist representation. Low thresholds allow small radical parties to enter parliament; whether that moderates or amplifies them is contested.

List PR achieves its central aim: vote and seat shares are closely aligned, especially with large districts and Sainte-Laguë or largest-remainder formulas. Research links it with multiparty systems, coalition government, higher representation of women (especially with list quotas), and somewhat higher turnout, though causation is difficult to separate from culture and history. Its costs are weaker personal accountability and more complex government formation. Much comparative work, including Carey and Hix, points to a middle ground: moderate district magnitudes or mixed systems can retain most proportionality while limiting fragmentation and preserving some local representation.

• Gallagher (1991), "Proportionality, Disproportionality and Electoral Systems", Electoral Studies90004-C)
• Iversen and Soskice (2006), "Electoral Institutions and the Politics of Coalitions", APSR
• Belgian Senate: history of parliamentary elections and the 1899 reform
• Arend Lijphart, Patterns of Democracy (2nd ed., Yale University Press, 2012)
• John M. Carey and Simon Hix, "The Electoral Sweet Spot", American Journal of Political Science 55(2) (2011)