Proceedings Abstracts of the Twenty-Fourth International Joint Conference on Artificial Intelligence

Lie on the Fly: Iterative Voting Center with Manipulative Voters / 2033
Lihi Naamani-Dery, Svetlana Obraztsova, Zinovi Rabinovich, Meir Kalech

Manipulation can be performed when intermediate voting results are known; voters might attempt to vote strategically and try and manipulate the results during an iterative voting process. When only partial voting preferences are available, preference elicitation is necessary. In this paper, we combine two approaches of iterative processes: iterative preference elicitation and iterative voting and study the outcome and performance of a setting where manipulative voters submit partial preferences. We provide practical algorithms for manipulation under the Borda voting rule and evaluate those using different voting centers: the Careful voting center that tries to avoid manipulation and the Naive voting center. We show that in practice, manipulation happens in a low percentage of the settings and has a low impact on the final outcome. The Careful voting center reduces manipulation even further.