BV2154 — Felsenthal Example 8: the absolute loser wins Approval — and three races give three winners¶
▶ Live on BetterVoting: vote · results ↗ (election wq6yv7).
15 voters. An absolute majority (8 of 15) rank April dead last — April is both the Condorcet loser and the absolute loser. One voter's approval-cutoff choice elects her anyway. And the same 15 ballots return three different winners across the three races: Approval → April, IRV → Clara, Ranked Robin → Bruce.
Source¶
Dan S. Felsenthal, "Review of Paradoxes Afflicting Various Voting Procedures Where One Out of m Candidates (m ≥ 2) Must Be Elected", University of Haifa / LSE, revised 26 May 2010; Appendix §A3, Example 8.
The election¶
No. of voters Ranking Approves
6 April > Bruce > Clara {April}
4 Bruce > Clara > April {Bruce}
1 Clara > April > Bruce {Clara, April} ← the strategic ballot
4 Clara > Bruce > April {Clara}
Social ordering Bruce > Clara > April (Bruce beats April 8–7 and Clara 10–5; Clara beats April 9–6). Approval totals: April 7, Bruce 4, Clara 5 → April, the candidate a majority ranked last — the Condorcet loser and absolute loser paradoxes under Approval, triggered by a single voter approving two. Compare BV2144, where Choose-One does the same with bullet votes only.
The ranked races disagree with Approval and with each other: IRV deletes the Condorcet winner Bruce (fewest first choices, 6/4/5) and elects Clara 9–6 — a Condorcet winner paradox — while Ranked Robin elects Bruce directly. One electorate, three winners: the tabulation, not the ballot, decides.
The races¶
| Race | BetterVoting | LH engine | Agree? |
|---|---|---|---|
| Approval (one strategic two-approval ballot) | April (7/4/5) | April | ✓ |
| IRV | Clara (Bruce deleted; 9–6) | Clara | ✓ |
| Ranked Robin | Bruce (Condorcet winner) | Bruce | ✓ |
Files: approval yaml · irv yaml · rr yaml · frozen export · mirrors: approval, irv, rr.