Manipulability of voting systems

Speaker : Francois Durand
Alcatel Lucent Bell Labs / INRIA
Date: 16/11/2011
Time: 2:00 pm - 3:00 pm
Location: LINCS Meeting Room 40


Voting systems allow competing entities to decide among different options. In order to ensure fairness between the competing entities, a strong requirement is to avoid manipulability by voters. Unfortunately, strong theoretical results show that, unless using some degenerated and a priori non-acceptable voting systems such as the dictatorial ones, any other voting system is susceptible to be manipulated by a single voter! However, very little is know about how much a voting system is manipulable. We evaluate different voting systems by quantifying their probability of manipulability on various kinds of voter populations. The results are very general and can be applied in any context where voting systems can be used.