TY - GEN

T1 - Exploring the no-show paradox for condorcet extensions using ehrhart theory and computer simulations

AU - Brandt, Felix

AU - Hofbauer, Johannes

AU - Strobel, Martin

N1 - Publisher Copyright:
© 2019 International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved. Social choice theory; voting; no-show paradox; Ehrhart theory.

PY - 2019

Y1 - 2019

N2 - Results from voting theory are increasingly used when dealing with collective decision making in computational multiagent systems. An important and surprising phenomenon in voting theory is the No-Show Paradox (NSP), which occurs if a voter is better off by abstaining from an election. While it is known that certain voting rules suffer from this paradox in principle, the extent to which it is of practical concern is not well understood. We aim at filling this gap by analyzing the likelihood of the NSP for six Condorcet extensions (Black's rule, Baldwin's rule, Nanson's rule, MaxiMin, Tideman's rule, and Copeland's rule) under various preference models using Ehrhart theory as well as extensive computer simulations. We find that, for few alternatives, the probability of the NSP is rather small (less than 4% for four alternatives and all considered preference models, except for Copeland's rule). As the number of alternatives increases, the NSP becomes much more likely and which rule is most susceptible to abstention strongly depends on the underlying distribution of preferences.

AB - Results from voting theory are increasingly used when dealing with collective decision making in computational multiagent systems. An important and surprising phenomenon in voting theory is the No-Show Paradox (NSP), which occurs if a voter is better off by abstaining from an election. While it is known that certain voting rules suffer from this paradox in principle, the extent to which it is of practical concern is not well understood. We aim at filling this gap by analyzing the likelihood of the NSP for six Condorcet extensions (Black's rule, Baldwin's rule, Nanson's rule, MaxiMin, Tideman's rule, and Copeland's rule) under various preference models using Ehrhart theory as well as extensive computer simulations. We find that, for few alternatives, the probability of the NSP is rather small (less than 4% for four alternatives and all considered preference models, except for Copeland's rule). As the number of alternatives increases, the NSP becomes much more likely and which rule is most susceptible to abstention strongly depends on the underlying distribution of preferences.

UR - http://www.scopus.com/inward/record.url?scp=85071830808&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:85071830808

T3 - Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS

SP - 520

EP - 528

BT - 18th International Conference on Autonomous Agents and Multiagent Systems, AAMAS 2019

PB - International Foundation for Autonomous Agents and Multiagent Systems (IFAAMAS)

T2 - 18th International Conference on Autonomous Agents and Multiagent Systems, AAMAS 2019

Y2 - 13 May 2019 through 17 May 2019

ER -