Sequential proportional approval voting

Condorcet methods Positional voting Cardinal voting Quota-remainder methods Approval-based committees Fractional social choice Semi-proportional representation By ballot type Pathological response Strategic voting Paradoxes of majority rule Positive results Sequential proportional approval voting (SPAV) or reweighted approval voting (RAV)[1] is an electoral system that extends the concept of approval voting to a multiple winner election.

[2] It was used (with adaptations for party lists) in Sweden from 1909 to 1921, when it was replaced by a cruder "party-list" style system as it was easier to calculate,[3][4] and is still used for some local elections.

[6] At each stage, the unelected candidate with the highest approval score is elected.

Other weighting formulas such as Sainte-Lague method may be used while still being referred to as SPAV.

[7] When comparing SPAV to the single transferable vote (STV), SPAV is better at selecting more central candidates, that represent all the voters, where STV is better at mimicking the distribution of the voters.

Each voter casts their vote by selecting the candidates they support.

The bottom row shows the number of votes each candidate received.

Because Candidate C has the most support, they are the first winner, w1, and their vote is not counted in later rounds.

Flow chart of SPAV calculation
Illustration of the example election. Candidates with the most votes wins for each round. When a candidate is elected they are removed for the next round.