Approximation Algorithms and Mechanism Design for Minimax Approval Voting

We consider approval voting elections in which each voter votes for a (possibly empty) set of candidates and the outcome consists of a set of k candidates for some parameter k, e.g., committee elections. We are interested in the minimax approval voting rule in which the outcome represents a compromise among the voters, in the sense that the maximum distance between the preference of any voter and the outcome is as small as possible. This voting rule has two main drawbacks. First, computing an outcome that minimizes the maximum distance is computationally hard. Furthermore, any algorithm that always returns such an outcome provides incentives to voters to misreport their true preferences. In order to circumvent these drawbacks, we consider approximation algorithms, i.e., algorithms that produce an outcome that approximates the minimax distance for any given instance. Such algorithms can be considered as alternative voting rules. We present a polynomial-time 2-approximation algorithm th...

• Type: Conference
• Year: 2010
• Where: AAAI
• Authors: Ioannis Caragiannis, Dimitris Kalaitzis, Evangelos Markakis
• Keywords: AAAI 2010, Algorithms, Approval Voting, Intelligent Agents, Voting Rules