Complexity of Conformant Election Manipulation

TL;DR

This paper investigates the computational complexity of election manipulation when voters' preferences define their own restrictions, ensuring the election outcome retains common domain restrictions after strategic actions.

Contribution

It introduces a new model where voters' preferences determine the restriction domain, analyzing the complexity of conformant manipulation in this setting.

Findings

Conformant manipulation retains common domain restrictions after strategic actions.

Complexity results vary depending on the specific election rules and restrictions.

The model relates to and extends existing manipulative action frameworks.

Abstract

It is important to study how strategic agents can affect the outcome of an election. There has been a long line of research in the computational study of elections on the complexity of manipulative actions such as manipulation and bribery. These problems model scenarios such as voters casting strategic votes and agents campaigning for voters to change their votes to make a desired candidate win. A common assumption is that the preferences of the voters follow the structure of a domain restriction such as single peakedness, and so manipulators only consider votes that also satisfy this restriction. We introduce the model where the preferences of the voters define their own restriction and strategic actions must ``conform'' by using only these votes. In this model, the election after manipulation will retain common domain restrictions. We explore the computational complexity of conformant manipulative actions and we discuss how conformant manipulative actions relate to other manipulative actions.