Journal of Computer and System Sciences
When are elections with few candidates hard to manipulate?
Journal of the ACM (JACM)
Average-case tractability of manipulation in voting via the fraction of manipulators
Proceedings of the 6th international joint conference on Autonomous agents and multiagent systems
Algorithms for the coalitional manipulation problem
Proceedings of the nineteenth annual ACM-SIAM symposium on Discrete algorithms
A sufficient condition for voting rules to be frequently manipulable
Proceedings of the 9th ACM conference on Electronic commerce
Generalized scoring rules and the frequency of coalitional manipulability
Proceedings of the 9th ACM conference on Electronic commerce
Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems - Volume 2
Elections Can be Manipulated Often
FOCS '08 Proceedings of the 2008 49th Annual IEEE Symposium on Foundations of Computer Science
Nonexistence of voting rules that are usually hard to manipulate
AAAI'06 Proceedings of the 21st national conference on Artificial intelligence - Volume 1
Junta distributions and the average-case complexity of manipulating elections
Journal of Artificial Intelligence Research
Universal voting protocol tweaks to make manipulation hard
IJCAI'03 Proceedings of the 18th international joint conference on Artificial intelligence
Hybrid voting protocols and hardness of manipulation
ISAAC'05 Proceedings of the 16th international conference on Algorithms and Computation
Parameterized complexity of candidate control in elections and related digraph problems
Theoretical Computer Science
Finite local consistency characterizes generalized scoring rules
IJCAI'09 Proceedings of the 21st international jont conference on Artifical intelligence
A scheduling approach to coalitional manipulation
Proceedings of the 11th ACM conference on Electronic commerce
Manipulation of copeland elections
Proceedings of the 9th International Conference on Autonomous Agents and Multiagent Systems: volume 1 - Volume 1
Towards a dichotomy for the Possible Winner problem in elections based on scoring rules
Journal of Computer and System Sciences
Comparing multiagent systems research in combinatorial auctions and voting
Annals of Mathematics and Artificial Intelligence
Is computational complexity a barrier to manipulation?
CLIMA'10 Proceedings of the 11th international conference on Computational logic in multi-agent systems
Complexity of safe strategic voting
SAGT'10 Proceedings of the Third international conference on Algorithmic game theory
Strategy-proof voting rules over multi-issue domains with restricted preferences
WINE'10 Proceedings of the 6th international conference on Internet and network economics
Multimode control attacks on elections
Journal of Artificial Intelligence Research
Ties matter: complexity of voting manipulation revisited
The 10th International Conference on Autonomous Agents and Multiagent Systems - Volume 1
An algorithm for the coalitional manipulation problem under Maximin
The 10th International Conference on Autonomous Agents and Multiagent Systems - Volume 2
Determining possible and necessary winners under common voting rules given partial orders
Journal of Artificial Intelligence Research
Taking the final step to a full dichotomy of the possible winner problem in pure scoring rules
Information Processing Letters
An NTU cooperative game theoretic view of manipulating elections
WINE'11 Proceedings of the 7th international conference on Internet and Network Economics
Where are the hard manipulation problems?
Journal of Artificial Intelligence Research
Computing the margin of victory for various voting rules
Proceedings of the 13th ACM Conference on Electronic Commerce
Coalitional voting manipulation: a game-theoretic perspective
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume One
The complexity of safe manipulation under scoring rules
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume One
On the complexity of voting manipulation under randomized tie-breaking
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume One
Ties matter: complexity of voting manipulation revisited
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume Three
Proceedings of the 11th International Conference on Autonomous Agents and Multiagent Systems - Volume 2
Convergence of iterative voting
Proceedings of the 11th International Conference on Autonomous Agents and Multiagent Systems - Volume 2
Manipulation under voting rule uncertainty
Proceedings of the 11th International Conference on Autonomous Agents and Multiagent Systems - Volume 2
Empirical analysis of plurality election equilibria
Proceedings of the 2013 international conference on Autonomous agents and multi-agent systems
Coalitional manipulation for Schulze's rule
Proceedings of the 2013 international conference on Autonomous agents and multi-agent systems
Schulze and ranked-pairs voting are fixed-parameter tractable to bribe, manipulate, and control
Proceedings of the 2013 international conference on Autonomous agents and multi-agent systems
How to change a group's collective decision?
IJCAI'13 Proceedings of the Twenty-Third international joint conference on Artificial Intelligence
Annals of Mathematics and Artificial Intelligence
A smooth transition from powerlessness to absolute power
Journal of Artificial Intelligence Research
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Understanding the computational complexity of manipulation in elections is arguably the most central agenda in Computational Social Choice. One of the influential variations of the the problem involves a coalition of manipulators trying to make a favorite candidate win the election. Although the complexity of the problem is well-studied under the assumption that the voters are weighted, there were very few successful attempts to abandon this strong assumption. In this paper, we study the complexity of the unweighted coalitional manipulation problem (UCM) under several prominent voting rules. Our main result is that UCM is NP-complete under the maximin rule; this resolves an enigmatic open question. We then show that UCM is NP-complete under the ranked pairs rule, even with respect to a single manipulator. Furthermore, we provide an extreme hardness-of-approximation result for an optimization version of UCM under ranked pairs. Finally, we show that UCM under the Bucklin rule is in P.