Size Approval Voting Rules
Tuva Vigen Bardal

Abstract:
The field of Voting Theory is concerned with the design and analysis of procedures for collective decision-making, called social choice functions, or voting rules. Many impossibility results having been provided, it is well known that there is no voting rule that will satisfy all kinds of desirable properties that could be asked for. An implication of such results is that the strengths and weaknesses of voting rules need to be assessed carefully so as to determine which rules are appropriate to use for different problems of collective decision-making. For rules in the class of Size Approval Voting rules, voters submit ballots corresponding to those alternatives they approve of, and their ballot is weighted based on the number of alternatives it contains. Despite its inherent simplicity and the prominence of some of its members, this class of voting rules has not been studied in great detail. This thesis studies the class of Size Approval Voting rules from several angles of Computational Social Choice, with the aim of better understanding the properties of the class and its members.