Title
On the Computational Hardness of Manipulating Pairwise Voting Rules.
Abstract
Standard voting rules usually assume that the preferences of voters are provided in the form of complete rankings over a fixed set of alternatives. This assumption does not hold in applications like recommendation systems where the set of alternatives is extremely large and only partial preferences can be elicited. In this paper, we study the problem of strategic manipulation of voting rules that aggregate voter preferences provided in the form of pairwise comparisons between alternatives. Our contributions are twofold: first, we show that any onto pairwise voting rule is manipulable in principle. Next, we analyze how the computational complexity of manipulation of such rules varies with the structure of the graph induced by the pairs of alternatives that the manipulator is allowed to vote over and the type of the preference relation. Building on natural connections between the pairwise manipulation and sports elimination problems (including a mixed-elimination variant that we introduce in this paper), we show that manipulating pairwise voting rules can be computationally hard even in the single-manipulator setting, a setting where most standard voting rules are known to be easy to manipulate.
Year
DOI
Venue
2016
10.5555/2936924.2936978
AAMAS
Keywords
Field
DocType
Social Choice Theory,Voting,Manipulation,Pairwise Preferences
Social choice theory,Pairwise comparison,Preference relation,Anti-plurality voting,Voting,Computer science,Cardinal voting systems,Artificial intelligence,Potentially all pairwise rankings of all possible alternatives,Machine learning,Condorcet method
Conference
Citations 
PageRank 
References 
0
0.34
21
Authors
4
Name
Order
Citations
PageRank
Vaish, Rohit1343.23
Neeldhara Misra234131.42
Agarwal, Shivani31194119.77
Avrim Blum47978906.15