Phragmén Rules for Degressive and Regressive Proportionality

Michał Jaworski; Piotr Skowron

IJCAI 2022poster6 citations

Phragmén Rules for Degressive and Regressive Proportionality

Abstract

We study two concepts of proportionality in the model of approval-based committee elections. In degressive proportionality small minorities of voters are favored in comparison with the standard linear proportionality. Regressive proportionality, on the other hand, requires that larger subdivisions of voters are privileged. We introduce a new family of rules that broadly generalize Phragmén's Sequential Rule spanning the spectrum between degressive and regressive proportionality. We analyze and compare the two principles of proportionality assuming the voters and the candidates can be represented as points in an Euclidean issue space.

Agent-based and Multi-agent Systems: Computational Social Choice

BibTeX

@inproceedings{ijcai2022p47,
  title     = {Phragmén Rules for Degressive and Regressive Proportionality},
  author    = {Jaworski, Michał and Skowron, Piotr},
  booktitle = {Proceedings of the Thirty-First International Joint Conference on
               Artificial Intelligence, {IJCAI-22}},
  publisher = {International Joint Conferences on Artificial Intelligence Organization},
  editor    = {Lud De Raedt},
  pages     = {328--334},
  year      = {2022},
  month     = {7},
  note      = {Main Track},
  doi       = {10.24963/ijcai.2022/47},
  url       = {https://doi.org/10.24963/ijcai.2022/47},
}