====================================================================== SOURCE FILE: equal_rank_clone_without.yaml TABULATED FILE: equal_rank_clone_without_tabulated.txt ====================================================================== election_title: "Equal ranks — Costa withdraws, and Split-IRV's winner flips to Alma" scenario_description: |- The clone-free half of Figure 9 from Théo Delemazure & Dominik Peters, "Generalizing Instant Runoff Voting to Allow Indifferences" (EC'24, arXiv:2404.11407). Same 45 voters, same cast, same ballots as equal_rank_clone_with.yaml with exactly one change: Costa is not running. Same cast because it is the same election with one thing changed. With the clone gone, Split-IRV elects Alma; with the clone in the race it elects the Chen/Costa ticket. Nothing about how anyone feels changed — only how many names their top preference was spread across. That flip is Split-IRV failing independence of clones, the axiom Tideman proved ordinary strict-ballot IRV satisfies and that gives instant runoff its main claim over Choose-One voting. Approval-IRV keeps the axiom (Theorem 3.2) and elects Alma in both files. STAR elects Alma here and in the companion file, so the clone is inert for STAR too — worth stating plainly rather than claiming: a score ballot already lets a voter rate two allies identically, so adding one changes no total that was not already recorded. For the Approval-IRV and Split-IRV counts run tools_adam/pref_voting_tabulation_engine/approval_irv_report.py. paradoxes: [clone-teaming, condorcet-winner] voting_method: STAR num_winners: 1 ballots: |- Count:Alma,Bruno,Chen 27:5,0,5 # Alma and Chen equal-first 12:3,5,0 # Bruno first, Alma second 6:3,0,5 # Chen first, Alma second expected_winners: [Alma] # file: equal_rank_clone_without.yaml ====================================================================== TABULATION RESULTS ====================================================================== === Equal ranks — Costa withdraws, and Split-IRV's winner flips to Alma === The clone-free half of Figure 9 from Théo Delemazure & Dominik Peters, "Generalizing Instant Runoff Voting to Allow Indifferences" (EC'24, arXiv:2404.11407). Same 45 voters, same cast, same ballots as equal_rank_clone_with.yaml with exactly one change: Costa is not running. Same cast because it is the same election with one thing changed. With the clone gone, Split-IRV elects Alma; with the clone in the race it elects the Chen/Costa ticket. Nothing about how anyone feels changed — only how many names their top preference was spread across. That flip is Split-IRV failing independence of clones, the axiom Tideman proved ordinary strict-ballot IRV satisfies and that gives instant runoff its main claim over Choose-One voting. Approval-IRV keeps the axiom (Theorem 3.2) and elects Alma in both files. STAR elects Alma here and in the companion file, so the clone is inert for STAR too — worth stating plainly rather than claiming: a score ballot already lets a voter rate two allies identically, so adding one changes no total that was not already recorded. For the Approval-IRV and Split-IRV counts run tools_adam/pref_voting_tabulation_engine/approval_irv_report.py. --- Runoff (Preference) Matrix --- Head-to-head / pairwise comparison Legend: For - Equal Support - Against * indicates Top 2 Finalist | * Alma | Bruno | * Chen | ------------------------------------------------------------- * Alma > | --- |33 - 0 - 12 |12 - 27 - 6 | Bruno > | 12 - 0 - 33 | --- |12 - 0 - 33 | * Chen > | 6 - 27 - 12 |33 - 0 - 12 | --- | [Condorcet Winner] Condorcet Winner: Alma — matches the STAR winner [Condorcet Loser] Condorcet Loser: Bruno — loses every head-to-head matchup --- STAR Voting Method (single winner) --- [STAR Voting] Tabulating 45 ballots. Count × Alma,Bruno,Chen 27 × 5, 0, 5 12 × 3, 5, 0 6 × 3, 0, 5 [Score Distribution] (how many ballots gave each star rating) Score Candidate 5 4 3 2 1 0 | Total Avg Alma 27 0 18 0 0 0 | 189 4.2 Bruno 12 0 0 0 0 33 | 60 1.3 Chen 33 0 0 0 0 12 | 165 3.7 [STAR Voting: Scoring Round] The two highest-scoring candidates advance to the next round. Alma -- 189 -- First place Chen -- 165 -- Second place Bruno -- 60 Alma and Chen advance. [STAR Voting: Automatic Runoff Round] The candidate preferred in the most head-to-head matchups wins. Alma -- 12 -- First place Chen -- 6 Equal Support -- 27 Alma wins. Runoff math: 45 ballots cast − 27 Equal Support (no preference between the two finalists) ── 18 voters with a preference (majority = 10) Alma 12 (67%) · Chen 6 (33%) [STAR Voting: Winner — STAR Voting Method (single winner)] Alma