The computational difficulty of manipulating an election


We show how computational complexity might protect the integrity of social choice. We exhibit a voting rule that efficiently computes winners but is computationally resistant to strategic manipulation. It is NP-complete for a manipulative voter to determine how to exploit knowledge of the preferences of others. In contrast, many standard voting schemes can be manipulated with only polynomial computational effort.

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Additional information

The authors appreciate many helpful comments and suggestions by the editor and three anonymous referees. We also thank Michel Balinski, Salvador Barbera, Jean-Pierre Barthelemy, and Peyton Young for stimulating discussions.

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Bartholdi, J.J., Tovey, C.A. & Trick, M.A. The computational difficulty of manipulating an election. Soc Choice Welfare 6, 227–241 (1989).

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  • Computational Complexity
  • Economic Theory
  • Computational Effort
  • Social Choice
  • Vote Rule