Single transferable vote resists strategic voting

@article{Bartholdi1991SingleTV,
  title={Single transferable vote resists strategic voting},
  author={John J. Bartholdi and James B. Orlin},
  journal={Social Choice and Welfare},
  year={1991},
  volume={8},
  pages={341-354}
}
We give evidence that Single Tranferable Vote (STV) is computationally resistant to manipulation: It is NP-complete to determine whether there exists a (possibly insincere) preference that will elect a favored candiate, even in an election for a single seat. Thus strategic voting under STV is qualitatively more difficult than under other commonly-used voting schemes. Furthermore, this resistance to manipulation is inherent to STV and does not depend on hopeful extraneous assumptions like the… Expand
Towards Computing Victory Margins in STV Elections
TLDR
Algorithms for computing lower and upper bounds on the MOV in STV elections are presented and in small instances, these algorithms are able to compute exact margins. Expand
Towards Computing the Margin of Victory in STV Elections
The Single Transferable Vote (STV) is a system of preferential voting employed in multi-seat elections. Each vote cast by a voter is a (potentially partial) ranking over a set of candidates. NoExpand
Non-dictatorial Social Choice Rules Are Safely Manipulable
When a number of like-minded voters vote strategically and have limited abilities to communicate the under and overshooting may occur when too few or too many of them vote insincerely. In this paperExpand
Single Transferable Vote: Incomplete Knowledge and Communication Issues
TLDR
The conclusion is that STV needs, in practice, much less information than in the best case, and not as much as in the worst case. Expand
An Empirical Study of the Manipulability of Single Transferable Voting
TLDR
Empirically, the manipulability of single transferable voting (STV) is studied to determine if computational complexity is really a barrier to manipulation. Expand
On The Complexity of Manipulating Elections
TLDR
This work studies the manipulation of voting schemes, where a voter lies about their preferences in the hope of improving the election's outcome, and shows that the hardness result for STV is true only if both the number of voters and theNumber of candidates are unbounded. Expand
Cognitive hierarchy and voting manipulation in k-approval voting
TLDR
Polynomial-time algorithms are provided, supporting the claim that strategic voting, albeit ubiquitous in collective decision making, is computationally hard if the manipulators try to reason about each other’s actions. Expand
Manipulability of Single Transferable Vote
  • T. Walsh
  • Computer Science
  • Computational Foundations of Social Choice
  • 2010
TLDR
Empirically the cost of manipulating the single transferable vote (STV) rule is studied, which appears to be one of the harder rules to manipulate since it involves multiple rounds and it is NP-hard for a single agent to manipulate without weights on the votes or uncertainty about how the other agents have voted. Expand
Average-case tractability of manipulation in voting via the fraction of manipulators
TLDR
It is analytically demonstrated that, with respect to a wide range of distributions over votes, the coalitional manipulation problem can be decided with overwhelming probability of success by simply considering the ratio between the number of truthful and untruthful voters. Expand
Copeland voting: ties matter
TLDR
This work shows that the problem of manipulation for unweighted Copelandα elections is NP-complete even if the size of the manipulating coalition is limited to two, and is the first one where an election system originally known to be vulnerable to manipulation via a single voter is shown to be resistant to manipulation through a coalition of a constant number of voters. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 40 REFERENCES
Susceptibility to manipulation
All positional voting procedures can be manipulated, so it is natural to question whether some of these systems are more susceptible to being manipulated than others. In this essay, thisExpand
Manipulation of Voting Schemes: A General Result
It has been conjectured that no system of voting can preclude strategic voting-the securing by a voter of an outcome he prefers through misrepresentation of his preferences. In this paper, for allExpand
The vulnerability of point-voting schemes to preference variation and strategic manipulation
AbstractThis essay measures and analyzes for a special class of point-voting schemes (the Borda method, plurality rule and the unrestricted point-voting scheme) sensitivity to preference variation (aExpand
Recognizing majority-rule equilibrium in spatial voting games
TLDR
The results suggest that majority-rule equilibrium can exist as a purely practical matter: when the number of voters and the dimension of the policy space are both large, it can be too difficult to find an alternative to defeat the status quo. Expand
Voting schemes for which it can be difficult to tell who won the election
We show that a voting scheme suggested by Lewis Carroll can be impractical in that it can be computationally prohibitive (specifically, NP-hard) to determine whether any particular candidate has wonExpand
Algorithm Supplement: Single Transferable Vote by Meek's Method
TLDR
The method was rediscovered, in a different formulation, by Woodall, but neither Meek nor Woodall dealt with certain detailed points, such as how to resolve a ‘tie’, so the system is extended to be complete. Expand
Monotonicity paradoxes in the theory of elections
  • P. Fishburn
  • Computer Science, Mathematics
  • Discret. Appl. Math.
  • 1982
TLDR
Several reasonable-sounding election procedures that are known to violate monotonicity are examined along with some new classes of non-monotonic procedures. Expand
To vote or not to vote: What is the quota?
  • R. Holzman
  • Computer Science, Mathematics
  • Discret. Appl. Math.
  • 1989
TLDR
It is shown here that PA and qCC are consistent iff q≥ (m−1) m or m ≤3, where m is the number of candidates and q-Core Condition requires that whenever there exists a candidate such that no other candidate is preferred to him/her by a fraction of q or more of the voters, the elected candidate should have this property. Expand
Monotonicity in Electoral Systems
Much of the literature concerning the relative merits of alternative electoral rules is centered around the extent to which particular rules select "representative" legislatures. And an importantExpand
Condorcet's principle implies the no show paradox
In elections with variable (and potentially large) electorates, Brams and Fishburn's No Show Paradox arises when a voter is better off not voting than casting a sincere ballot.. Scoring methods doExpand
...
1
2
3
4
...