Voting Behaviour on Free Votes: Simply a Matter of Preferences?

On the Manipulability of Votes: The Case of Approval Voting

The famous result of Gibbard and Satterthwaite shows that every voting procedure is manipulable if the voters can have any preferences over the candidates. That is, a voter may improve the voting result by not voting according to his true preference. Approval voting, introduced by Brams and Fishburn, is not manipulable if preferences are dichotomous: each voter only distinguishes between accept...

Electronic Voting and Electronic Counting of Votes

The Impact of Changing Voting Systems on Residual Votes

Problems in the 2000 presidential election, especially in Florida, initiated a large-scale shift toward new voting technology. Using cross-sectional and longitudinal data, we report on the effects of changes in voting systems in Florida and Michigan. The variety of initial conditions and the numerous changes make these excellent case studies. We find that reforms succeeded in reducing the resid...

The Computational Impact of Partial Votes on Strategic Voting

In many real world elections, agents are not required to rank all candidates. We study three of the most common methods used to modify voting rules to deal with such partial votes. These methods modify scoring rules (like the Borda count), elimination style rules (like single transferable vote) and rules based on the tournament graph (like Copeland) respectively. We argue that with an eliminati...

Is Approval Voting Optimal Given Approval Votes?

Some crowdsourcing platforms ask workers to express their opinions by approving a set of k good alternatives. It seems that the only reasonable way to aggregate these k-approval votes is the approval voting rule, which simply counts the number of times each alternative was approved. We challenge this assertion by proposing a probabilistic framework of noisy voting, and asking whether approval v...