Swap Bribery
نویسندگان
چکیده
In voting theory, bribery is a form of manipulative behavior in which an external actor (the briber) offers to pay the voters to change their votes in order to get her preferred candidate elected. We investigate a model of bribery where the price of each vote depends on the amount of change that the voter is asked to implement. Specifically, in our model the briber can change a voter’s preference list by paying for a sequence of swaps of consecutive candidates. Each swap may have a different price; the price of a bribery is the sum of the prices of all swaps that it involves. We prove complexity results for this model, which we call swap bribery, for a broad class of voting rules, including variants of approval and kapproval, Borda, Copeland, and maximin.
منابع مشابه
A Unifying Framework for Manipulation Problems
Manipulation models for electoral systems are a core research theme in social choice theory; they include bribery (unweighted, weighted, swap, shift, . . . ), control (by adding or deleting voters or candidates), lobbying in referenda and others. We develop a unifying framework for manipulation models with few types of people, one of the most commonly studied scenarios. A critical insight of ou...
متن کاملFrom Election Fraud to Finding the Dream Team: A Study of the Computational Complexity in Voting Problems and Stability in Hedonic Games
In this thesis we study computational aspects of different voting problems and cooperative games with hedonic preferences. For two well-studied voting systems, namely Bucklin and fallback voting, we present a detailed study of the computational complexity of common manipulative attacks on elections. We fully describe the classical worst-case complexity of manipulation, bribery, and swap bribery...
متن کاملFrugal Bribery in Voting
Bribery in elections is an important problem in computational social choice theory. We introduce and study two important special cases of the classical $BRIBERY problem, namely, FRUGAL-BRIBERY and FRUGAL-$BRIBERY where the briber is frugal in nature. By this, we mean that the briber is only able to influence voters who benefit from the suggestion of the briber. More formally, a voter is vulnera...
متن کاملVoting and Bribing in Single-Exponential Time
We introduce a general problem about bribery in voting systems. In the R-Multi-Bribery problem, the goal is to bribe a set of voters at minimum cost such that a desired candidate wins the manipulated election under the voting rule R. Voters assign prices for withdrawing their vote, for swapping the positions of two consecutive candidates in their preference order, and for perturbing their appro...
متن کاملOn elections with robust winners
We study the sensitivity of election outcomes to small changes in voters’ preferences. We assume that a voter may err by swapping two adjacent candidates in his vote; we would like to check whether the election outcome would remain the same given up to δ errors. We show that this problem can be viewed as the destructive version of the unit-cost swap bribery problem, and demonstrate that it is p...
متن کامل