In the 2019 UK general election, the Liberal Democrats received 11.6% of all votes cast and won 12 out of 650 seats — 1.8% of parliament. In the same election, the Scottish National Party received 3.9% of votes and won 48 seats — 7.4% of parliament. Three times fewer votes, four times as many seats. This is not an anomaly or a malfunction. It is the entirely predictable result of an electoral system designed around something other than proportionality.
Electoral systems — the rules that convert votes into seats — are one of the most consequential and least-discussed aspects of democracy. They determine which parties can survive, how many parties typically compete, how often governments need coalition partners, and how closely the composition of parliament reflects the preferences of voters. There is no neutral choice.
First-Past-The-Post
Each constituency elects one representative; the candidate with the most votes wins, even without a majority.
First-Past-The-Post (FPTP) is the oldest and simplest electoral system. The country is divided into single-member constituencies. Voters choose one candidate. The candidate with the most votes wins the seat — even if they received only 30% of the vote, as long as no one else received more. There is no threshold, no proportionality, and no second round.
The UK 2019 election illustrates both the appeal and the problem. The Conservatives won 43.6% of votes and 56.2% of seats — a large majority from a minority of the electorate. Labour won 32.2% of votes and 31.1% of seats. The Liberal Democrats' 11.6% earned them 1.8% of seats, because their voters were spread relatively evenly across constituencies rather than concentrated in a few. The Green Party won 2.7% of the national vote and one seat.
FPTP tends to produce two dominant parties, because votes for smaller parties are almost always "wasted" — they do not contribute to winning any seat. Over time, voters learn to vote strategically rather than sincerely, supporting the least-bad large party rather than the party they actually prefer. Governments tend to have large parliamentary majorities, which makes governing easier but makes parliaments less representative.
Proportional Representation
Seats are distributed to parties roughly in proportion to their national vote share.
Proportional representation (PR) is the most common family of electoral systems in established democracies. The core principle is that a party that receives 20% of the vote should win approximately 20% of seats. In practice, the exact method — D'Hondt, Sainte-Lague, Hare quota — affects how closely the outcome approaches perfect proportionality, but all PR systems are dramatically more representative than FPTP.
The Netherlands uses the purest form: the entire country is a single constituency, and any party that crosses the threshold of roughly one seat's worth of votes (about 0.67%) wins representation. The 2021 Dutch election produced seventeen parties in parliament, with the largest, VVD, winning only 21.9% of seats. The resulting coalition negotiations took 271 days. This is the trade-off: PR gives smaller parties a voice but makes majority governments rare and coalition-building complex.
Spain uses PR within provincial constituencies, which introduces some distortion — smaller provinces elect fewer members, which benefits larger parties — but still produces far more proportional outcomes than FPTP. Israel, with a single national constituency and a low threshold, tends toward extreme fragmentation, sometimes producing 10 or more parties in parliament and requiring complex multi-party coalitions.
Mixed systems
Combines single-member constituencies with a proportional party-list correction.
Germany's electoral system — formally called Mixed Member Proportional (MMP) — attempts to get the best of both worlds. Each voter casts two votes: one for their local constituency candidate (determined by FPTP) and one for a national party list (determined by PR). The key insight is that the party-list vote, not the constituency vote, determines each party's total share of seats. Constituency wins are compensated for by reducing the number of list seats that party receives.
The result is roughly proportional at the national level while preserving local representation. New Zealand adopted the same system in 1996 after a referendum, and Scotland and Wales use a related variant for their devolved parliaments. The main complication is "overhang seats" — when a party wins more constituencies than its proportional share would entitle it to, parliament must grow to accommodate the surplus. The German Bundestag has voted in recent elections with over 700 members because of this effect, despite a nominal size of 598.
Two-round systems
If no candidate wins a majority in round one, the top two (or more) face off in a runoff.
Two-round voting is designed to ensure that the winner has genuine majority support. If no candidate reaches 50% in the first round, the top two candidates advance to a second round, held weeks later. Voters who supported eliminated candidates can then choose between the two finalists.
France uses two-round voting for both its presidential election and its legislative elections, though with different qualification rules. For the presidency, only the top two advance regardless of margin. For the legislature, any candidate who clears 12.5% of registered voters in the first round can advance — which sometimes produces three-way runoffs and complex tactical decisions about whether to stand or step aside.
Poland uses two-round voting for its presidential election: ElectioMap covered the 2025 Polish presidential election, where no candidate reached 50% in round one, as is typical. The system strongly incentivizes first-round coalition-building, since parties know their eliminated candidates' voters need somewhere to go in round two.
Ranked choice and preferential voting
Voters rank candidates by preference; lower-ranked candidates are eliminated and their votes redistributed until someone has a majority.
Australia has used preferential voting — known elsewhere as ranked-choice or instant-runoff voting — for its House of Representatives since 1918. Voters number candidates in order of preference. If no candidate has a majority of first-preference votes, the candidate with the fewest votes is eliminated and their ballots redistributed according to the second preference marked on each. This continues until one candidate has more than half the votes.
Ireland and Malta use the Single Transferable Vote (STV), a more complex variant used in multi-member constituencies, which produces more proportional outcomes than simple ranked choice while preserving voter choice between candidates of the same party. ElectioMap covers Malta's parliamentary elections, which have produced some of the highest voter turnout figures in the democratic world — consistently above 90% — partly attributed to the STV system's ability to make every vote feel consequential.
No system is neutral
Every electoral system embeds a set of choices about what democracy should optimize for. FPTP prioritizes decisive government and clear accountability over representativeness. PR prioritizes representativeness over simplicity and governability. Mixed systems try to balance the two and end up with complexity. Two-round voting prioritizes majority legitimacy at the cost of a second trip to the polls.
These choices have real consequences. Countries with PR systems tend to have more parties, more coalition governments, and higher voter turnout. Countries with FPTP tend to have more stable majority governments but more "wasted" votes and stronger pressures toward a two-party system. Neither is simply better; both are defensible. The important thing is to understand which rules apply when reading a given election's results — because the same vote shares in different systems would produce dramatically different outcomes.