5 June 2023, Computational Social Choice Seminar, Hugo Gilbert
In this presentation, we introduce new power measures to evaluate the a priori voting power of voters in liquid democracy elections and in variants of the proxy voting setting. We argue that our power measures are natural extensions of the standard Penrose-Banzhaf measure in simple voting games. While the problem of computing the criticality of a voter turns out to be #P-hard, we show that, for specific settings, such as for proxy voting, recursive formulas can compute these measures for weighted voting games in pseudo-polynomial time. We highlight the theoretical properties of our measures and provide numerical results to illustrate how enabling or restricting the possible delegations can alter voters' voting power. THis is joint work with Rachael Colley and Théo Delemazure.
For more information on the Computational Social Choice Seminar, please consult https://staff.science.uva.nl/u.endriss/seminar/.