---
title: "Winner Determination in Sequential Majority Voting"
authors:
  - "Jérôme Lang"
  - "Maria Silvia Pini"
  - "Francesca Rossi"
  - "Kristen Brent Venable"
  - "Toby Walsh"
doi: ""
url: "https://ijcai.org/proceedings/2007/221"
pdf: "https://ijcai.org/proceedings/2007/0221.pdf"
venue: "Proceedings of the Twentieth International Joint Conference on Artificial Intelligence"
year: 2007
pages: "1372-1376"
track: ""
keywords:
---

# Winner Determination in Sequential Majority Voting

Jérôme Lang, Maria Silvia Pini, Francesca Rossi, Kristen Brent Venable, Toby Walsh

*Proceedings of the Twentieth International Joint Conference on Artificial Intelligence*, pages 1372-1376.

## Abstract

Preferences can be aggregated using voting rules. We consider here the family of rules which perform a sequence of pairwise majority comparisons between two candidates. The winner thus depends on the chosen sequence of comparisons, which can be represented by a binary tree. We address the difficulty of computing candidates that win for some trees, and then introduce and study the notion of fair winner, i.e. candidates who win in a balanced tree. We then consider the situation where we lack complete informations about preferences, and determine the computational complexity of computing winners in this case.